Entry Word: jack

Function: noun

Meaning: 1 slangsomething (as pieces of stamped metal or printed paper) customarily and legally used as a medium of exchange, a measure of value, or a means of payment <I'd buy that watch, but I don't have the jack> — see money
2 a piece of cloth with a special design that is used as an emblem or for signaling <a Portuguese ship flying the national jack> — see flag 1
3 an adult male human being <hey, jack, can you spare some change?> — see man 1
4 one who operates or navigates a seagoing vessel <the streets of the old seaport were once full of jacks, harlots, and other dockside denizens> — see sailor