Etymograph

English

happy ending

From happy (adjective) + ending (noun).

A compound of happy + ending

Middle English happy ‘fortunate’

English happy

Proto-Indo-European *h₂ent- ‘face’

…

Proto-West Germanic *andijōn ‘to end’

Old English endian ‘to end’

Old English endung

Middle English endynge

English ending

Today it means

noun A conclusion to a story in which all the loose ends of the plot are tied up, and all the main characters are left in a state of contentment or happiness.

Language periods are conventional ranges, not dates for this word.

Etymograph / happy ending