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• seal
  seal

  noun

  an embossed emblem, figure, symbol, word, letter, etc., used as attestation or evidence of authenticity.
• SEAL
  SEAL

  noun

  a member of the U.S. Navy’s special operations forces.

seal

¹ American  

[seel] / sil /

noun

1. an embossed emblem, figure, symbol, word, letter, etc., used as attestation or evidence of authenticity.

   Without the seal, the certificate is useless.

2. a stamp, medallion, ring, etc., engraved with such a device, for impressing paper, wax, lead, or the like.

   The king took the seal from his finger and applied it to the document.

3. the impression so obtained.

   It was unmistakably the royal seal on the document.

4. a mark or symbol attached to a legal document and imparting a formal character to it, originally wax with an impression.

   Part of his job was stamping the lawyer's seal next to each of her signatures.

5. a piece of wax or similar adhesive substance so attached to an envelope, folded document, etc., that it must be broken when the object is opened, insuring that the contents have not been tampered with or altered.

6. anything that tightly or completely closes or secures a thing, as closures or fastenings for doors and railroad cars, adhesive stamps and tapes used to secure the flap of an envelope, etc.

7. something that keeps a thing secret.

   Her vow was the seal that kept her silent.

8. a decorative stamp, especially as given to contributors to a charitable fund.

   a Christmas seal.

9. a mark, sign, symbol, or the like, serving as visible evidence of something.

10. anything that serves as assurance, confirmation, or bond.

    She gave the plan her seal of approval.

11. Plumbing.

    1. a small amount of water held by a trap to exclude foul gases from a sewer or the like.

    2. the depth of the part of the water that actually excludes the gases.

12. British. the seals, the tokens or signs of public office.

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verb (used with object)

1. to affix a seal to in authorization, testimony, etc.

2. to assure, confirm, or bind with or as if with a seal.

   They sealed the bargain with a handshake.

3. to impress a seal upon as evidence of legal or standard exactness, measure, quality, etc.

4. to close by any form of fastening that must be broken before access can be gained.

5. to fasten or close tightly by or as if by a seal.

   She was sealing envelopes. My lips are sealed.

6. to decide irrevocably.

   to seal someone's fate.

7. to grant under one's seal or authority, as a pardon.

8. Mormon Church. to make (a marriage or adoption) forever binding; solemnize.

9. Electricity. to bring (a plug and jack or socket) into locked or fully aligned position.

verb phrase

1. seal off

   1. to close hermetically.

      to seal off a jar.

   2. to block (an entrance, area, etc.) completely so as to prevent escape or entrance.

      The police sealed off the area after the bomb threat was received.

idioms

1. seal / close the deal. see seal the deal.

2. set one's seal to, to give one's approval to; authorize; endorse.

   Both families have set their seal to the marriage.

seal ² American  

[seel] / sil /

noun

• seals,
  plural
• seal
  plural

1. any of numerous marine carnivores of the suborder Pinnipedia, including the eared or fur seals, as the sea lion, and the earless or hair seals, as the harbor seal.

2. the skin of such an animal.

3. leather made from this skin.

4. the fur of the fur seal; sealskin.

5. a fur used as a substitute for sealskin.

6. a dark, gray brown.

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verb (used without object)

1. to hunt, kill, or capture seals.

seal ³ American  

[seel] / sil /

verb (used with object)

Falconry.

1. seel.

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SEAL ⁴ American  

[seel] / sil /

noun

1. a member of the U.S. Navy’s special operations forces.

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seal ¹ British  

/ siːl /

noun

1. any pinniped mammal of the families Otariidae (eared seals) and Phocidae (earless seals) that are aquatic but come on shore to breed See eared seal earless seal

2. any earless seal (family Phocidae ), esp the common or harbour seal or the grey seal ( Halichoerus grypus )

3. sealskin

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verb

1. (intr) to hunt for seals

seal ² British  

/ siːl /

noun

1. a device impressed on a piece of wax, moist clay, etc, fixed to a letter, document, etc, as a mark of authentication

2. a stamp, ring, etc, engraved with a device to form such an impression

3. a substance, esp wax, so placed over an envelope, document, etc, that it must be broken before the object can be opened or used

4. any substance or device used to close or fasten tightly

5. a material, such as putty or cement, that is used to close an opening to prevent the passage of air, water, etc

6. a small amount of water contained in the trap of a drain to prevent the passage of foul smells

7. an agent or device for keeping something hidden or secret

8. anything that gives a pledge or confirmation

9. a decorative stamp often sold in aid of charity

10. Also called: seal of confession.  RC Church the obligation never to reveal anything said by a penitent in confession

11. 1. to mark with one's sign or seal

    2. to endorse

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verb

1. to affix a seal to, as proof of authenticity

2. to stamp with or as if with a seal

3. to approve or authorize

4. (sometimes foll by up) to close or secure with or as if with a seal

   to seal one's lips

   seal up a letter

5. (foll by off) to enclose (a place) with a fence, wall, etc

6. to decide irrevocably

7. Mormon Church to make (a marriage or adoption) perpetually binding

8. to subject (the outside of meat, etc) to fierce heat so as to retain the juices during cooking

9. to close tightly so as to render airtight or watertight

10. to paint (a porous material) with a nonporous coating

11. to consolidate (a road surface) with bitumen, tar, etc

seal Scientific  

/ sēl /

1. Any of various aquatic carnivorous mammals of the families Phocidae and Otariidae, having a sleek, torpedo-shaped body and limbs that are modified into paddlelike flippers. Seals live chiefly in the Northern Hemisphere and, like walruses, are pinnipeds.

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seal More Idioms  

More idioms and phrases containing seal

• lips are sealed
• set one's seal on
• signed, sealed and delivered

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Other Word Forms

Derived Forms

• resealable
  adjective
• seal-like
  adjective
• sealable
  adjective
• seallike
  adjective

Inflected Forms

Nouns

• seal
  plural
• seals
  plural

Etymology

Origin of seal¹

First recorded in 1250–1300; Middle English noun sel(e), selle, seal(e) “an identifying impressed mark on a document,” from Old French seel, seal(e), seil ( French sceau ), from unattested Vulgar Latin sigellum, segellum, from Latin sigillum “statuette, flgure on a signet ring,” diminutive of signum “an identifying mark written, impressed, or affixed; point, impression”; verb sele(n), seale(n), seil(en), from Old French seeler, sealer, seieler, derivative of seel; see also sign

Origin of seal²

First recorded before 900; Middle English sel(e), cel(e), zel(e), Old English seolh; cognate with Old Norse selr, Old High German selah

Origin of SEAL⁴

se(a) a(ir) l(and) (team)

Explanation

A seal can be either the cute mammal at the aquarium balancing a beach ball on its nose, or the fancy stamp on your diploma that acts as an official "seal of approval" from your school. Seal is a tricky word since its meanings are so diverse. One type of seal lives in water, coming ashore to breed, give birth, and nurse their young. The largest type of seal — the elephant seal — can weigh 6,000 pounds! On the other hand, seal can also mean a stamp that may be placed on a document to show that the document is official and authentic. And, if you want to make sure that your document is safe in its envelope, you might need to seal (make tight) the envelope with some tape.

Example Sentences

See Examples For:

seal SEAL seals

One of them was a former Monsanto worker who spent three years helping to seal toxic waste underground and said staff had "cheap" protective equipment and were not told what they were burying.

From BBC ● Aug. 27, 2026

California law often requires county governments to seal or destroy juvenile-detention records after a certain period, often making it impossible to verify if a plaintiff was ever in their custody.

From The Wall Street Journal ● Aug. 27, 2026

The arm-wrestling will kick off in earnest at a Brussels summit in October, with a likely second meeting in November, before a grand finale in December when leaders will look to seal the deal.

From Barron's ● Aug. 27, 2026

For a lawsuit to go forward under the Child Victims Act, two declarations must be filed under seal to the court.

From Los Angeles Times ● Aug. 26, 2026

The Gran gestured for the Spares to come forward, and as they stood there lined up, she made a giant X over their heads, magic to seal the contract until the impossible task began.

From "Witchlings" by Claribel A. Ortega

Vantor’s 10 satellites cover 7 million square kilometers of Earth a day, hitting any one point on the globe 12 to 15 times, said Will Cocos, Vantor’s chief transformation officer and a former Navy SEAL.

From The Wall Street Journal ● Jun. 5, 2026

"The best-case scenario is we put this in every single school in America and then never have to use it, right? Because it's got a deterrent quality to it," said King, a former Navy SEAL.

From Barron's ● May 15, 2026

In one moment during the speech, Trump paid tribute to the widow of a fallen Navy SEAL.

From Slate ● Feb. 24, 2026

The rural dirt farmer versus the decorated Navy SEAL.

From New York Times ● May 17, 2024

But there’s no way I’ll ever end up a Navy SEAL.

From "Red Kayak" by Priscilla Cummings

Newer cars and trucks employ opposite frequency technology, which lowers road noise, silicone-based coating on door seals that cuts virtually all high-frequency whistling, and noise-dampening designs on windows, to name a few technologies.

From Los Angeles Times ● Aug. 10, 2026

This primary production supports a wider food web that includes fish, crustaceans and seals.

From Science Daily ● Aug. 3, 2026

From naughty penguins to ungovernable elephant seals, funny animals attracting attention on the internet is nothing new.

From BBC ● Jul. 24, 2026

They have been documented engaging in "wave washing" -- cooperating to create choppy waters that knock seals off sheets of ice so they can be more easily captured and eaten.

From Barron's ● Jul. 23, 2026

I thought about the seals that were multiplying off Cape Cod and how if I ever saw them hanging around the beach, I would stay out of the water.

From "The Line Tender" by Kate Allen

Related Words

• close
• enclose
• isolate
• plug
• secure
• shut
• stop