mild-mannered

the compound adjective 'mild-mannered' is a relatively modern english formation, emerging in the 19th century. its first element, 'mild', descends from the old english 'milde', which itself stems from proto-germanic mildijaz, carrying the core sense of gentle and merciful. the second element, 'mannered', originates from the noun 'manner', derived from the latin 'manuarius' (of the hand), which evolved in old french to denote method or way of doing things. the combination literally means 'having a gentle way or method', a logical and transparent description for a person whose habitual conduct is characterized by calmness and politeness.

Structure: mild (gentle) + mannered (having a manner) mild (old english, meaning gentle, merciful, kind); mannered (english, from manner (way of behaving) + -ed (adjective suffix meaning 'having the quality of'))