sillyyoudaoicibaDictYouDict[silly 词源字典]
silly: [OE] In one of the more celebrated semantic volte-faces in the history of the English lexicon, silly has been transformed over the past millennium from ‘blessed, happy’ to ‘stupid’. The word goes back ultimately to a prehistoric West Germanic *sǣliga, a derivative of *sǣli ‘luck, happiness’. It reached Old English as gesǣlig, still meaning ‘happy’, but as it evolved formally in Middle English through seely to silly, its meaning developed via ‘blessed’, ‘pious’, ‘innocent, harmless’, ‘pitiable’, and ‘feeble’ to ‘feeble in mind, foolish’. The related German selig retains its original meaning ‘happy, blessed’.
[silly etymology, silly origin, 英语词源]
silly (adj.)youdaoicibaDictYouDict
Old English gesælig "happy, fortuitous, prosperous" (related to sæl "happiness"), from Proto-Germanic *sæligas (cognates: Old Norse sæll "happy," Old Saxon salig, Middle Dutch salich, Old High German salig, German selig "blessed, happy, blissful," Gothic sels "good, kindhearted"), from PIE *sele- "of good mood; to favor," from root *sel- (2) "happy, of good mood; to favor" (cognates: Latin solari "to comfort," Greek hilaros "cheerful, gay, merry, joyous").
This is one of the few instances in which an original long e (ee) has become shortened to i. The same change occurs in breeches, and in the American pronunciation of been, with no change in spelling. [Century Dictionary]
The word's considerable sense development moved from "happy" to "blessed" to "pious," to "innocent" (c. 1200), to "harmless," to "pitiable" (late 13c.), "weak" (c. 1300), to "feeble in mind, lacking in reason, foolish" (1570s). Further tendency toward "stunned, dazed as by a blow" (1886) in knocked silly, etc. Silly season in journalism slang is from 1861 (August and September, when newspapers compensate for a lack of hard news by filling up with trivial stories). Silly Putty trademark claims use from July 1949.