mansuetude (n.)youdaoicibaDictYouDict[mansuetude 词源字典]
"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" (see manual (adj.)) + suescere "to accustom, habituate," from PIE *swdh-sko-, from *swedh- (see sodality), extended form of root *s(w)e- (see idiom).[mansuetude etymology, mansuetude origin, 英语词源]
tame (adj.)youdaoicibaDictYouDict
early Middle English tame "in a state of subjection, physically subdued, restrained in behavior" (c. 1200); of animals "domesticated, reclaimed from wildness," also, of persons, "meek, gentle-natured, compliant, intent on homely or domestic activities" (mid-13c.), from oblique forms of Old English tom, tam "domesticated, docile," from Proto-Germanic *tamaz (cognates: Old Norse tamr, Old Saxon, Old Frisian, Middle Low German, Middle Dutch tam, Old High German zam, German zahm "tame," Gothic tamjan "to tame"), from PIE *deme- "to constrain, to force, to break (horses)" (cognates: Sanskrit damayati "tames;" Persian dam "a tame animal;" Greek daman "to tame, subdue," dmetos "tame;" Latin domare "to tame, subdue;" Old Irish damnaim "I tie up, fasten, I tame, subdue").

A possible ulterior connection is with PIE *dem- "house, household" (see domestic (adj.)). Meaning "spiritless, weak, dull, uninspiring, insipid" is recorded from c. 1600. Related: Tamely; tameness.