kidneyyoudaoicibaDictYouDict[kidney 词源字典]
kidney: [14] The origins of kidney are a matter of guesswork rather than certain knowledge. Probably the most widely accepted theory is that the -ey element represents ey, the Middle English word for ‘egg’, in allusion to the shape of the kidneys. The first syllable is more problematical, but one possible source is Old English cwith ‘womb’ or the related Old Norse kvithr ‘belly, womb’, in which case kidney would mean etymologically ‘belly-egg’.
=> egg[kidney etymology, kidney origin, 英语词源]
kidney (n.)youdaoicibaDictYouDict
early 14c., of unknown origin, originally kidenere, perhaps a compound of Old English cwið "womb" (see bowel) + ey "egg" (see egg (n.)) in reference to the shape of the organ. Figurative sense of "temperament" is from 1550s. Kidney bean is from 1540s, so called for its shape.