"tameness, gentleness, mildness," late 14c., from Latin mansuetudo "tameness, mildness, gentleness," noun of state from past-participle stem of mansuescere "to tame," literally "to accustom to the hand," from manus "hand" (from PIE root *man- (2) "hand") + suescere "to accustom, habituate," from PIE *swdh-sko-, from *swedh- (see sodality), extended form of root *s(w)e- (see idiom).