trapyoudaoicibaDictYouDict[trap 词源字典]
trap: [OE] The precise origins of trap are obscure. It goes back to an Old English træppe, and it has various relatives in the modern Germanic and Romance languages – Flemish trape, French trappe, Portuguese trapa, for instance – but its ultimate ancestry has never been unravelled. Its application to a small carriage emerged in the 19th century; it may be short for rattle-trap ‘rickety vehicle’.
[trap etymology, trap origin, 英语词源]
trap (v.)youdaoicibaDictYouDict
late 14c., "ensnare (an animal), catch in a trap; encircle; capture," from trap (n.) or from Old English betræppan. Figurative use is slightly earlier (late 14c.). Related: Trapped; trapping.
trap (n.)youdaoicibaDictYouDict
"contrivance for catching unawares," late Old English træppe, treppe "snare, trap," from Proto-Germanic *trep- (cognates: Middle Dutch trappe "trap, snare"), related to Germanic words for "stair, step, tread" (Middle Dutch, Middle Low German trappe, treppe, German Treppe "step, stair," English tread (v.)), and probably literally "that on or into which one steps," from PIE *dreb-, extended form of root *der- (1), an assumed base of words meaning "to run, walk, step." Probably akin to Old French trape, Spanish trampa "trap, pit, snare," but the exact relationship is uncertain.

Sense of "deceitful practice, device or contrivance to betray one" is first recorded c. 1400. Meaning "U-shaped section of a drain pipe" is from 1833. Slang meaning "mouth" is from 1776. Speed trap recorded from 1908. Trap door "door in a floor or ceiling" (often hidden and leading to a passageway or secret place) is first attested late 14c.