Seal is the word you need in almost every situation. It means to close something tightly, to fasten it with a stamp or emblem, or to settle a matter for good. It is also the name of a marine mammal. Seel is a rare verb from falconry that means to close a bird’s eyes by sewing the eyelids.
The two words sound identical, so the wrong spelling slips in easily, especially in phrases such as seal the deal or seal an envelope. This guide explains both words, their origins, and when each is correct. It also includes examples, common mistakes, a decision guide, and a short quiz.
Comparison Overview
The table shows how the two words differ at a glance.
| Feature | Seal | Seel |
| Status | Common, standard English | Rare, specialist and historical |
| Part of speech | Noun and verb | Verb |
| Core meaning | An animal; a stamp or closure; to close, secure, or finalize | To close a hawk’s eyes by sewing the eyelids; archaic: to close or blind the eyes |
| Pronunciation | Same as seel | Same as seal |
| Example | She sealed the envelope. | Falconers once seeled young hawks. |
Definition of Seal
Seal has three main noun meanings:
- The animal: Merriam-Webster describes seals as marine mammals of cold regions with webbed flippers adapted for swimming.
- A stamp or emblem: the dictionary lists something that secures a document, such as a wax seal, and a symbol of an office.
- A tight closure: a barrier that stops air or liquid from passing, as in the seal on a jar.
As a verb, seal means to mark with a seal or to close as if with a seal. It also has the figurative sense of finalizing something, as in seal the deal.
Definition of Seel
Merriam-Webster defines seel as a verb meaning to close a bird’s eyes, such as a hawk’s, by drawing threads through the eyelids. It also records an archaic sense: to close one’s own eyes. Dictionary.com adds the sense “to blind.”
The verb is regular. Its forms are seels, seeled, and seeling. Today it appears mostly in discussions of historical falconry, in older literature, and in word lists.
Older dictionaries such as Webster’s 1913 also record obsolete senses, including a ship leaning to one side and a noun meaning good fortune. Those senses are no longer in ordinary use.
Main Differences Between Seal and Seel
- Frequency: Seal is everywhere in modern English. Seel is rare.
- Grammar: Seal is a noun and a verb. Seel is only a verb.
- Meaning: Seal covers closing, stamping, and finalizing. Seel covers closing or sewing eyes shut.
- Register: Seal suits every register. Seel suits historical, literary, or technical falconry writing.
- Spelling pattern: Seal uses ea. Seel uses ee.
- Sound: Both are pronounced the same, so only context tells them apart in writing.
Etymology and Historical Background
The two words come from unrelated sources. They ended up sounding alike by coincidence, and both involve closing something.
Origin of Seal
English has two different words spelled seal.
The animal word comes from Old English seolh, and the stamp word comes from Old French and Latin sigillum, a diminutive of signum, meaning “sign.” Etymonline says the origin of the animal word is unknown and suggests a possible borrowing from Finnic.
Merriam-Webster notes that Middle English also spelled the stamp word seel. That old spelling is one reason the confusion feels natural, but modern English uses seal.
Origin of Seel
Merriam-Webster traces seel to Middle English silen, from French ciller, then Medieval Latin ciliare and Latin cilium, meaning “eyelid.” It dates the first known use to the 15th century. Sources describe the French stage differently, some calling it Middle French and others Anglo-French. They agree on the Latin root, which is also the source of the word cilia.
Common Contexts Where Seal Appears
- Animals: The seal basked on the rocks.
- Official documents: A court seal, a notary seal, or a company seal marks a document as authentic.
- Packaging and mail: Envelopes, jars, bags, and boxes are sealed.
- Home and building work: The word sealant dates from 1945 and is formed from seal plus -ant.
- Military: SEAL, written in capitals, is the acronym used for the United States Navy’s special forces.
- Figurative use: People seal a friendship, a victory, or someone’s fate.
Grammar Guide
Both words are regular. Seal is a noun with the plural seals. For the animal, Merriam-Webster notes that the plural may also be seal. Its verb forms are seals, sealed, and sealing.
How Each Term Is Used in Sentences
Seal
- As a noun: The letter carried the mayor’s seal.
- As a verb with an object: He sealed the jar tightly.
- Without an object: The lid seals when you press it down.
Seel
- With an object: In early training, the handler would seel the young hawk’s eyes.
- In the past tense: The bird had been seeled for several days.
Seel almost always takes a direct object, usually the bird or its eyes.
Common Mistakes Learners Make
- Spelling an everyday action with seel.
- Incorrect: Please seel the envelope before posting it.
- Correct: Please seal the envelope before posting it.
- Seel does not mean to close a letter.
- Misspelling an idiom.
- Incorrect: The product earned a seel of approval.
- Correct: The product earned a seal of approval.
- In this idiom, the word means an official stamp of endorsement.
- Misspelling the animal.
- Incorrect: A seel sat on the ice.
- Correct: A seal sat on the ice.
- The animal is always seal.
- Misspelling the verb forms.
- Incorrect: The box was seeled with tape.
- Correct: The box was sealed with tape.
- Seeled belongs only to the rare verb seel.
Simple Rules to Remember
- If you are not writing about falconry or old literature, use seal.
- Seal covers the animal, the stamp, the closure, and the act of closing or finalizing.
- Seel is only a verb, and a rare one.
- Both words sound alike, so check the spelling when you write.
Quick Tips for Writing and Speaking
A memory aid for seel: it has two e’s, like two eyes. That ties it to its meaning of closing the eyes. For the everyday word, think of ea as in sea, because seals live near it.
When speaking, no choice is needed because the words sound the same. When writing, search your draft for “seel” and ask whether you are discussing a hawk’s eyelids. If not, change it to seal.
When to Use Each One
Use Seal When:
- Closing an envelope, jar, package, or crack.
- Naming the marine animal.
- Describing an official stamp, emblem, or certification.
- Finalizing an agreement, result, or outcome.
Use Seel When:
- Writing about historical falconry methods.
- Quoting or discussing older literature that uses the word.
- Explaining the word itself, as in a vocabulary lesson.
When NOT to Use Each One
Do Not Use Seal When:
- You specifically mean the falconry practice and are writing in a technical or historical context where seel is the established term.
Do Not Use Seel When:
- You mean closing a letter, jar, or box.
- You mean the animal or an official stamp.
- You are writing for a general audience, since most readers will take it as a typo.
Which One to Use (Decision Guide)
- Ask whether you mean closing, fastening, stamping, certifying, finalizing, or the animal. If yes, write seal.
- Ask whether you mean sewing a hawk’s eyelids shut, or you are using the archaic sense of closing the eyes. If yes, seel may be correct.
- If you are writing for a general audience and unsure, use seal.
- Check fixed phrases: seal an envelope, seal of approval, and seal the deal all use seal.
- Match the verb form: sealed and sealing for seal, seeled and seeling for seel.
Real-World Practical Examples
Seal Examples
- Office: Please seal the contract in the folder before it goes to the client.
- Kitchen: She sealed the leftovers in a container and put them in the fridge.
- Home repair: He sealed the gap around the window before winter.
- Legal: The document was signed and stamped with the official seal.
- Wildlife: A grey seal surfaced near the boat.
- Sport: A late goal sealed the win for the home team.
Seel Examples
- Historical: The medieval falconer would seel the new hawk before its training began.
- Dictionary study: The verb seel appears in some word lists as a rare term from falconry.
- Literary: Older poems sometimes use the archaic sense of seel to mean closing someone’s eyes.
Seal or seel synonym
Seal has many synonyms, and each fits a different sense. Seel has very few.
| Word | Sense | Common synonyms | Note |
| Seal | Close tightly | close, shut, fasten, secure | Everyday use |
| Seal | Stamp or authenticate | stamp, certify, mark | Official documents |
| Seal | Settle | clinch, finalize, secure | Often figurative |
| Seel | Close the eyes | blind, close, shut | Rare; falconry and archaic use |
WordWeb classes seel as a type of blind. Chambers also glosses it with hoodwink.
Seal or seel an envelope
The correct phrase is seal an envelope. It describes pressing the flap closed so the contents are secure. A sealed envelope has been closed and is meant to stay closed until the recipient opens it.
Seel an envelope is a spelling error, because seel never refers to closing paper or mail.
- Correct: She licked the flap and sealed the envelope.
- Correct: The bid must arrive in a sealed envelope.
- Incorrect: He seeled the envelope and posted it.
Etymonline notes that the old verb unseal meant to remove or break a seal. That makes unsealed the natural opposite of sealed.
Seal or seel of approval
The correct phrase is seal of approval. Here, seal means an official stamp or mark showing that something has been endorsed. A product, a film, or a restaurant can earn a seal of approval, and the related phrase stamp of approval means nearly the same thing.
Seel of approval is an error. Seel cannot work in this phrase because it is a verb, and the idiom needs a noun.
- Correct: The book received the teachers’ seal of approval.
- Incorrect: The gadget earned a seel of approval.
Seal or seel the deal
The correct phrase is seal the deal. Merriam-Webster lists seal the deal as an idiom built on the sense of putting an authenticating seal on a document. The picture is of a stamp that makes an agreement final. In everyday speech, it means to finalize an agreement or to make success certain.
Seel the deal is wrong. It would mean something like closing the eyes of a deal, which makes no sense.
- Correct: A strong final offer sealed the deal.
- Incorrect: A late call seeled the deal.
Seal something
Seal is usually transitive. You seal something, and the object tells the reader what was closed, stamped, or finalized.
- Seal + object: She sealed the bottle.
- Seal off: Police sealed off the street.
- Seal up: He sealed up the old doorway.
- Seal in: The wrapper seals in freshness.
- Seal with: They sealed the agreement with a handshake.
- Passive: The package was sealed at the factory.
Seal can also appear without an object, as in the lid seals tightly. The noun sealant names a substance used to seal a surface or container. Seel does not appear in any of these everyday patterns.
Self-Assessment (Fill in the Blanks)
Choose seal or seel for each sentence, or give the correct form.
- Please ______ the box with tape before shipping. (seal / seel)
- A ______ slid off the rock into the water. (seal / seel)
- The new toy earned a ______ of approval from parents. (seal / seel)
- A last-minute goal helped ______ the victory. (seal / seel)
- In old falconry, a handler might ______ a young hawk’s eyes. (seal / seel)
- Choose the correct past tense for the everyday verb: (a) sealed (b) seeled
- Fix the error: “She seeled the envelope and handed it over.”
- True or false: Seal and seel are pronounced differently.
Answers
- seal
- seal
- seal
- seal
- seel (in the specialist falconry sense)
- (a) sealed
- She sealed the envelope and handed it over.
- False. They sound the same.
Final Verdict
Use seal unless you are deliberately writing about the old falconry practice or quoting older literature. The two words sound the same, but only seal covers the animal, the stamp, the closure, and the act of finalizing a deal. If you are unsure, seal is almost certainly the right choice.
Frequently Asked Questions
Is seel a real word?
Yes, but it is rare. Merriam-Webster lists it as a verb meaning to close a hawk’s eyes by threading the eyelids. It is not used in everyday English.
Are seal and seel homophones?
Yes. They are pronounced the same, so spelling is the only way to tell them apart in writing.
Why do both words involve closing something?
It is a coincidence. Seal comes from Latin sigillum, meaning a small sign or stamp. Seel comes from Latin cilium, meaning eyelid. The words came into English by different routes and now sound alike.
What is the plural of seal?
The usual plural is seals. For the animal, Merriam-Webster also allows the plural seal.
Is SEAL capitalized in Navy SEAL?
Yes. It is written in capitals because it is an acronym for the Navy’s Sea, Air, and Land teams.
Is seal a noun or a verb?
Both. As a noun, it can be an animal, a stamp, or a closure. As a verb, it means to close, stamp, or finalize.
Is seeling the same as ceiling?
No. They sound alike but are unrelated. Seeling is a form of the rare verb seel, while ceiling is the upper surface of a room.
Conclusion
Seal is the everyday word for the animal, the stamp, the tight closure, and the act of finalizing a matter. Seel is a rare verb tied to falconry and archaic writing. When you are describing an envelope, a jar, a deal, or an endorsement, write seal. Save seel for historical or literary contexts where the old sense is clearly intended.