Definition of fid

• n. - A square bar of wood or iron, used to support the topmast, being passed through a hole or mortise at its heel, and resting on the trestle trees.
• n. - A wooden or metal bar or pin, used to support or steady anything.
• n. - A pin of hard wood, tapering to a point, used to open the strands of a rope in splicing.
• n. - A block of wood used in mounting and dismounting heavy guns.