Definify.com

Webster 1913 Edition

Verb.

[1st pref.

un-

To loose from pins; to remove the pins from; to unfasten;

as, to

unpin

a frock; to

unpin

a frame

Verb.

To loose from pins; to unfasten what is held together by pins; as, to unpin a frock; to unpin the frame of a building.

unpin ‎(third-person singular simple present unpins, present participle unpinning, simple past and past participle unpinned)