late 14c., mincen, "to chop (meat, herbs, onions, etc.) in little pieces," from Old French mincier "make into small pieces," from Vulgar Latin *minutiare "make small," from Late Latin minutiæ "small bits," from Latin minutus "small" (from PIE root *mei- (2) "small").
From 1540s in reference to speech, "to utter primly or in a half-spoken way as affected delicacy, clip affectedly in imitation of elegance," of words or language, "to restrain in the interest of decorum," 1590s. The meaning "walk with short or precise steps or with affected nicety" is from 1560s. The etymological sense is "to make less, make small." Related: Minced; mincing.