verb
To have faith in (someone); to trust.
Chiefly followed by that or to: to formally affirm or promise (something).
Chiefly of a man: to formally promise to marry (someone, chiefly a woman); to be engaged to; also, to marry (someone); to espouse.
Chiefly followed by to, unto, or with: often of a parent or guardian: to formally promise that (someone) be married to another person; to affiance, to betroth.
Followed by in, to, or unto: to bind or pledge (someone or something) to another person or thing.
Chiefly followed by in, on, and upon: to rely on, to trust.
noun
(slang) An affidavit to be signed by a contest winner to confirm eligibility.