seal

seal — noun

1. a large grey sea mammal that has smooth skin, short fur, and flat limbs called f

1.nounB2
Definition

a large grey sea mammal that has smooth skin, short fur, and flat limbs called flippers that help it swim, and that lives in water but hauls itself up onto beaches or sheets of frozen sea to rest

Example

A seal popped its head above the water near the fishing boat.

Léa watched a seal sunbathing on a rocky beach during her trip.

collocation: a seal sunbathing / a seal on the beach

Common collocations
  • grey seal
  • harbour seal
  • baby seal
  • seal pup
  • seal colony
Synonyms
  • sea lion

    a different group of pinnipeds with visible ear flaps and the ability to walk on land

  • walrus

    a large Arctic pinniped with long tusks, not a true seal

Usage Note

Frequently used with species names: 'grey seal', 'harbour seal', 'elephant seal'. The young are called 'pups'.

Common Mistakes

A sealion sat on the rock' (when you mean the animal with ear flaps).
A sea lion sat on the rock, and a seal lay next to it.
Sea lions have visible ear flaps and can walk on land; true seals have no ear flaps and wiggle on their bellies.

2. a ring or strip made of rubber, plastic, or metal that fits between two surfaces

2.noun
Definition

a ring or strip made of rubber, plastic, or metal that fits between two surfaces where pipes or openings meet, preventing the movement of liquid or gas from one side to the other

Example

The plumber replaced the rubber seal around the kitchen tap.

collocation: rubber seal

A broken seal on the freezer door caused ice to build up inside.

Common collocations
  • rubber seal
  • door seal
  • window seal
  • replace the seal
  • check the seal
Synonyms
  • gasket

    a mechanical seal between two flat surfaces, usually in an engine or pipe joint

  • washer

    a flat ring used to distribute pressure or prevent leakage in a screw or tap

  • O-ring

    a circular seal with a round cross-section, used in hydraulic systems

Usage Note

Commonly used in the context of plumbing, cooking, and vehicle parts ('door seal', 'window seal'). The material (rubber, silicone, metal) is usually specified.

3. a thin sheet of paper, plastic, or metal fitted across the mouth of a bottle, ja

3.noun
Definition

a thin sheet of paper, plastic, or metal fitted across the mouth of a bottle, jar, or box, designed to be torn or cut away before you can take out what is inside, and serving as evidence that the item has not been used or tampered with

Example

Sahil broke the plastic seal and opened the bottle of mineral water.

collocation: break the seal

The safety seal on the medicine bottle was still intact when it arrived.

collocation: safety seal

Common collocations
  • break the seal
  • safety seal
  • foil seal
  • wax seal
  • tamper-evident seal
  • intact seal
Synonyms
  • lid

    a removable or hinged cover, not designed to show tampering

  • cap

    a small lid that screws or snaps onto a bottle, often covering a seal underneath

  • wrapper

    a paper or plastic covering that may or may not serve as a tamper indicator

Usage Note

Often called 'safety seal' or 'tamper-evident seal'. Found on food containers, medicine bottles, and drink bottles. The seal is designed so that it cannot be removed without leaving visible damage.

Common Mistakes

I opened the seal and drank the water.
I broke the seal and drank the water.
'Break the seal' is the natural collocation for opening a sealed container for the first time.

4. an official design or stamp pressed onto a document, sometimes using wax or ink,

4.noun
Definition

an official design or stamp pressed onto a document, sometimes using wax or ink, to prove that it is authentic, legal, or approved by an authority

Example

The contract had a red wax seal from the mayor's office.

collocation: wax seal

Feng stamped the company seal at the bottom of the agreement page.

Common collocations
  • wax seal
  • official seal
  • company seal
  • presidential seal
  • notary seal
  • under seal
Synonyms
  • stamp

    a rubber device that prints ink onto paper; less formal than a wax or embossed seal

  • emblem

    a symbolic design representing an organisation, not used for authentication

  • insignia

    a badge or symbol of office or membership, usually on clothing or flags

Usage Note

Frequently used with 'wax seal' (a traditional method using melted wax) or 'company seal' (a rubber stamp that imprints a logo or name). The phrase 'under seal' means a document has been formally authenticated.

Common Mistakes

Please put your seal signature here.
Please put your seal here.
A seal is pressed or stamped, not signed. If you mean a handwritten name, use 'signature'.

5. a soldier belonging to a specially trained US Navy unit whose members carry out

5.noun
Definition

a soldier belonging to a specially trained US Navy unit whose members carry out dangerous missions across oceans, skies, and battlefields; 'SEAL' is an acronym whose letters stand for operations on the Sea, in the Air, and on Land

Example

Linh's cousin trained for two years to become a Navy SEAL.

collocation: become a Navy SEAL

A Navy SEAL team rescued the hostages during the night.

collocation: Navy SEAL team

Common collocations
  • Navy SEAL
  • SEAL team
  • become a SEAL
  • SEAL training
Synonyms
  • special forces soldier

    a general term for an elite soldier, not specific to the US Navy

  • commando

    a soldier trained for quick, surprise attacks; more general than Navy SEAL

Usage Note

Always capitalised as 'Navy SEAL' or 'SEAL'. Refers to a specific US military unit (Naval Special Warfare Development Group). In other countries, similar units have different names.

Common Mistakes

He joined the navy seal team.
He joined a Navy SEAL team.
'Navy SEAL' is a proper noun and should be capitalised.
Phrasal verbs

seal off

phrasal verb

to prevent people from entering an area, usually by putting up barriers or locking doors

Police sealed off the street after a gas leak was reported.

Firefighters sealed off the building while they checked for damage.

Idioms

a statement or sign that shows official acceptance or that something is of good quality

The project received the seal of approval from the city council.

My grandmother gave her seal of approval to the wedding dress I chose.

completely final and official, because all the necessary documents have been signed and marked with a seal

The deal is signed and sealed, so we can start building next month.

Once the contract is signed and sealed, there is no going back.

used to promise that you will not tell anyone a secret

Do not worry about your secret — my lips are sealed.

Mira promised to keep the news quiet and said, 'My lips are sealed.'

to make a particular outcome certain, usually a negative or unavoidable one

The missing evidence sealed the defendant's fate.

His careless mistake sealed the team's fate in the championship match.

seal — verb

Word family

  • sealed
    adjectiveB2
  • sealer
    nounC1
  • sealing
    nounC1
  • unseal
    verbC1

Synonym discussion

Sense: verb/4

All four words describe making something definite, but they differ in tone and scope. 'Seal' (verb sense 4) adds a ceremonial or decisive finality — you seal a deal with a handshake or seal a victory with a goal; it also implies that the thing is now secure and cannot be undone. 'Confirm' is more neutral and factual: you confirm a booking, a time, or a suspicion, without the sense of a grand conclusion. 'Finalize' is procedural and administrative: you finalize a plan, a budget, or a schedule — it suggests checking boxes on a checklist. 'Settle' focuses on resolving remaining doubts or disputes: you settle a disagreement, a debt, or an insurance claim. In business, 'seal a deal' emphasises the dramatic moment of commitment; 'finalize the deal' suggests paperwork is being processed. In sports, 'seal the victory' sounds like a decisive blow; 'confirm the victory' sounds oddly clinical. Choose 'seal' when you want to convey certainty and finality with emotional weight; choose 'confirm' for routine verification; choose 'finalize' for formal procedures; choose 'settle' when the matter involved conflict or uncertainty.

Common collocations

Etymology

LatinOld FrenchEnglish

The word 'seal' in English actually comes from two different historical roots that happen to look and sound the same today. The noun senses meaning 'stamp' or 'mark' (and all related verb senses about closing and confirming) come from Old French 'seel', which traces back through Latin 'sigillum' (a small mark or figure) to Latin 'signum' (a mark or sign). This is the same root that gives us 'sign', 'signal', and 'signature'. Meanwhile, the animal — the grey, flippered sea mammal — comes from Old English 'seolh', a Germanic word with relatives in Old Norse 'selr' and Dutch 'zeehond' (literally 'sea dog'). The two words have been identical in spelling since Middle English, but they have never been related.