blanch (v.1)youdaoicibaDictYouDict[blanch 词源字典]
c. 1400, transitive, "to make white, turn pale," from Old French blanchir "to whiten, wash," from blanc "white" (11c.; see blank (adj.)). Originally "to remove the hull of (almonds, etc.) by soaking." Intransitive sense of "to turn white" is from 1768. Related: Blanched; blanching.[blanch etymology, blanch origin, 英语词源]
blanch (v.2)youdaoicibaDictYouDict
"to start back, turn aside," 1570s, variant of blench. Related: Blanched; blanching.