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

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.

the impression so obtained

It was unmistakably the royal seal on the document.

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

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.

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.

something that keeps a thing secret

Her vow was the seal that kept her silent.

a decorative stamp, esp. as given to contributors to a charitable fund

a Christmas seal.

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

anything that serves as assurance, confirmation, or bond

She gave the plan her seal of approval.

Plumbing .

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

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

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

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

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

They sealed the bargain with a handshake.

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

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

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

She was sealing envelopes. My lips are sealed.

to decide irrevocably

to seal someone's fate.

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

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

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

seal off,

to close hermetically

to seal off a jar.

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.

set one's seal to

to give one's approval to; authorize; endorse

Both families have set their seal to the marriage.

noun

disapproval , refusal

verb

loosen , open , unseal , delay , put off , refuse

noun

allowance , assurance , attestation , authorization , cachet , confirmation , imprimatur , insignia , notification , permission , permit , ratification , signet , sticker , tape , tie , bulla , great seal , privy seal

verb

close , cork , enclose , fasten , gum , isolate , paste , plaster , plug , quarantine , secure , segregate , shut , stop , stopper , stop up , waterproof , assure , attest , authenticate , clinch , conclude , confirm , consummate , establish , ratify , settle , shake hands on , stamp , validate , assurance , brand , cachet , cap , confine , finalize , guarantee , hallmark , insignia , pledge , sigil , sign , signet , sticker , symbol , token