Būm'kīn, n.

n. [From boom, and the dim. term. kīn.] (Naut.) (a.) Pieces of timber projecting from each bow of a vessel, to haul the fore tack to, called a fork-bumkin; also, from each quarter, for the standing part of the main brace, and called brace-bumkin. (b.) A small out-rigger over the stern of a boat, to extend the mizzen.