bee's knees (n.)youdaoicibaDictYouDict[bee's knees 词源字典]
1923, a survivor of a fad around this year for slang terms denoting "excellence" and based on animal anatomy. Also existed in the more ribald form bee's nuts. Other versions that lasted through the century are cat's whiskers (1923), cat's pajamas, cat's meow. More obscure examples are canary's tusks, cat's nuts and flea's eyebrows. The fad still had a heartbeat in Britain at the end of the century, as attested by the appearance of dog's bollocks in 1989. Bee's knee was used as far back as 1797 for "something insignificant."[bee's knees etymology, bee's knees origin, 英语词源]
defibrillation (n.)youdaoicibaDictYouDict
1940, in reference to heartbeat, from de- + fibrillation "a beating in an abnormal way," especially of the muscles of the heart that contract irregularly in this condition.
heart-beat (n.)youdaoicibaDictYouDict
also heartbeat, 1850, "a pulsation of the heart," from heart (n.) + beat (n.). From its coinage used as a figure for "a very brief time."
pacemaker (n.)youdaoicibaDictYouDict
also pace-maker, 1884, originally a rider or boat that sets the pace for others in training. Meaning "the node of the heart which determines the beat rate" is from 1910; sense of "man-made device for stimulating and regulating heartbeat" is from 1951. From pace (n.) + maker.
tachycardia (n.)youdaoicibaDictYouDict
"rapid heartbeat," 1868, Modern Latin, coined 1867 by German-born physician Hermann Lebert (1813-1878) from tachy- "swift" + Latinized form of Greek kardia "heart," from PIE root *kerd- (1) "heart" (see heart (n.)).