Broach (�), n. [OE. broche, F. broche, fr. LL. brocca; prob. of Celtic origin; cf. W. proc thrust, stab, Gael. brog awl. Cf. Brooch.] 1. A spit.
He turned a broach that had worn a crown.
Bacon.
2. An awl; a bodkin; also, a wooden rod or pin, sharpened at each end, used by thatchers. Forby.
3. (Mech.) (a) A tool of steel, generally tapering, and of a polygonal form, with from four to eight cutting edges, for smoothing or enlarging holes in metal; sometimes made smooth or without edges, as for burnishing pivot holes in watches; a reamer. The broach for gun barrels is commonly square and without taper. (b) A straight tool with file teeth, made of steel, to be pressed through irregular holes in metal that cannot be dressed by revolving tools; a drift.
4. (Masonry) A broad chisel for stonecutting.
5. (Arch.) A spire rising from a tower.
6. A clasp for fastening a garment. See Brooch.
7. A spitlike start, on the head of a young stag.
8. The stick from which candle wicks are suspended for dipping. Knight.
9. The pin in a lock which enters the barrel of the key.