blemish (v.)youdaoicibaDictYouDict[blemish 词源字典]
early 14c., "to hurt, damage," from Old French blemiss- "to turn pale," extended stem of blemir, blesmir "to make pale; stain, discolor," also "to injure" (13c., Modern French blêmir), probably from Frankish *blesmjan "to cause to turn pale," or some other Germanic source, from Proto-Germanic *blas "shining, white," from PIE root *bhel- (1) "to shine, flash, burn" (see bleach (v.)).

The order of appearance of senses in Middle English is "hurt, damage;" "impair morally, sully" (late 14c.); "mar, spoil, injure" (early 15c.); "to mar the beauty or soundness of" (mid-15c.). Related: Blemished; blemishing.[blemish etymology, blemish origin, 英语词源]
blemish (n.)youdaoicibaDictYouDict
1520s, from blemish (v.).