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2 verb
seal2 [transitive]
1 also seal up to close an entrance or a container with something that stops air, water etc from coming in or out of it:
The window was sealed shut.
seal a joint/crack/opening/gap
A quick way to seal awkward gaps is to use a foam filler.
Dried milk is kept in hermetically sealed (=very tightly closed) containers.
2 if a building, area, or country is sealed, no one can enter or leave it:
Authorities plan to seal the border.
3 to close an envelope, package etc by using something sticky to hold its edges in place:
He wrote the address and sealed the envelope.
4 to cover the surface of something with something that will protect it:
Wooden decks should be sealed to prevent cracking.

seal somebody's fate

to make something, especially something bad, sure to happen:
The outbreak of war sealed the government's fate.

seal a deal/bargain/pact etc

to make an agreement more formal or definite

seal a victory/win/match

to make a victory certain:
Smith's goal sealed the victory.

➔ somebody's lips are sealed

at lip (5)

; ➔ all signed and sealed

at sign2 (6)

seal something ↔ in

phrasal verb
to stop something that is inside something else from getting out:
Fry the meat quickly to seal in the juices.

seal something ↔ off

phrasal verb
to stop people from entering an area or building, because it is dangerous:
Following a bomb warning, police have sealed off the whole area.

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