/fid/ , 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.
[ 1605-15; orig. uncert. ]