English
hatpin
From hat + pin.
Proto-Germanic *hattuz ‘hat’
Proto-West Germanic *hattu ‘hat’
Old English hætt
Middle English hat ‘a hat or cap’
English hat
Proto-Indo-European *bend- ‘protruding object, pointed peg, nail, edge’
Proto-Germanic *pinnaz
Proto-West Germanic *pinn ‘pin, nail’
Old English pinn ‘pin, peg, bolt’
Middle English pinne
English pin
Today it means
noun A long straight pin, often with a decorative head, used to secure a woman's hat to her hair.
Language periods are conventional ranges, not dates for this word.
Etymograph / hatpin