trapezium (n.)youdaoicibaDictYouDict[trapezium 词源字典]
1560s, from Late Latin trapezium, from Greek trapezion "irregular quadrilateral," literally "a little table," diminutive of trapeza "table, dining table," from tra- "four" (see four) + peza "foot, edge," related to pous, from PIE root *ped- (1) "a foot" (see foot (n.)). Before 1540s, Latin editions of Euclid used the Arabic-derived word helmariphe. As the name of a bone in the wrist, it is recorded from 1840.[trapezium etymology, trapezium origin, 英语词源]