a waist-length garment worn for protective purposes:
a bulletproof vest.
a sleeveless, waist- or hip-length garment made of various materials, with a front opening usually secured by buttons, a zipper, or the like, worn over a shirt, blouse, dress, or other article for style or warmth:
a sweater vest; a down vest.
British. an undervest or undershirt.
a long garment resembling a cassock, worn by men in the time of Charles II.
c.1425, "to put in possession of a person," from M.Fr. vestir, from M.L. vestire "to put into possession, to invest," from L. vestire "to clothe," related to vestis "garment, clothing," from PIE *wes- "to clothe" (see wear). Vested "established, secured, settled" is attested from 1766.
1613, "loose outer garment" (worn by men in Eastern countries or in ancient times), from Fr. veste, from It. vesta, veste "robe, gown," from L. vestis, from vestire "to clothe" (see vest (v.)). The sleeveless garment worn by men beneath the coat was introduced by Charles II.
"The King hath yesterday, in Council, declared his resolution of setting a fashion for clothes .... It will be a vest, I know not well how; but it is to teach the nobility thrift." [Pepys, "Diary," Oct. 8, 1666]