Pronunciation: (fid),[key] —n.Naut. 1. a stout bar of wood or metal placed across a lower spar so as to support a higher one.
2. a stout bar used to hold a running bowsprit in its extended position.
3. a wooden or metal pin for parting strands of a rope.
4. a bar or pin used as a key or toggle.
a combining form meaning “divided,” “lobed,” occurring in adjectives borrowed from Latin (bifid); on this model, used in the formation of compound words (pinnatifid).