English

mainpin

main + pin

A compound of main + pin

Middle English mayn

English main

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 kingbolt; kingpin.

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