late 14c., "to pull or gather up," earlier "to pluck, stretch" (implied in tucker "one who finishes clothes by stretching them on tenters, late 13c. as a surname), probably from Middle Low German or Middle Dutch tucken "pull up, draw up, tug" (cognate with Old English tucian "mistreat, torment," and related to Old English togian "to pull," German zucken; see tow (v.)). Sense of "thrust into a snug place" is first recorded 1580s. Slang meaning "to consume, swallow, put into one's stomach" is recorded from 1784. Related: Tucked; tucking.
late 14c., "flattened fold in clothing, pleat," from tuck (v.). As a folded-up diving position, from 1951.