Engagement
来自Big Physics
early 17th century (in the general sense ‘a legal or moral obligation’): French, from engager ‘to pledge’ (see engage).
wiktionary
From French engagement.
etymonline
engagement (n.)
1620s, "formal promise," from engage + -ment. Meaning "a battle or fight between armies or fleets" is from 1660s; sense of "state of having entered into a promise of marriage" is from 1742; meaning "appointment" is from 1806. Engagement ring attested by 1840.
