imbecileyoudaoicibaDictYouDict[imbecile 词源字典]
imbecile: [16] Etymologically imbecile means ‘without support’, hence ‘weak’. It came via French from Latin imbēcillus, a compound adjective formed from the prefix in- ‘not’ and an unrecorded *bēcillum, a diminutive variant of baculum ‘stick’ (from which English gets bacillus and bacterium). Anyone or anything without a stick or staff for support is by extension weak, and so the Latin adjective came to mean ‘weak, feeble’. This broadened out to ‘weak in mind’, and was even used as a noun for ‘weak-minded person’, but English did not adopt these metaphorical uses until the late 18th century.
=> bacillus, bacterium[imbecile etymology, imbecile origin, 英语词源]
imbecile (adj.)youdaoicibaDictYouDict
1540s, imbecille "weak, feeble" (especially in reference to the body), from Middle French imbecile (15c.), from Latin imbecillus "weak, feeble" (see imbecility). Sense shifted to mental weakness from mid-18c. (compare frail, which in provincial English also could mean "mentally weak"). As a noun, "feeble-minded person," it is attested from 1802. Traditionally an adult with a mental age of roughly 6 to 9 (above an idiot but beneath a moron).