What does "broach" mean?

Additional senses

1. 2.(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.
2. 3.(Masonry) A broad chisel for stonecutting.
3. 4.(Arch.) A spire rising from a tower. [Local, Eng.]
4. 5.A clasp for fastening a garment. See Brooch.
5. 6.A spitlike start, on the head of a young stag.
6. 7.The stick from which candle wicks are suspended for dipping. Knight.
7. 8.The pin in a lock which enters the barrel of the key.
8. 9.To spit; to pierce as with a spit. I'll broach the tadpole on my rapier's point. Shak.
9. 10.To tap; to pierce, as a cask, in order to draw the liquor. Hence: To let out; to shed, as blood. Whereat with blade, with bloody blameful blade, He bravely broached his boiling bloody breast. Shak.
10. 11.To open for the first time, as stores. You shall want neither weapons, victuals, nor aid; I will open the old armories, I will broach my store, and will bring forth my stores. Knolles.
11. 12.To make public; to utter; to publish first; to put forth; to introduce as a topic of conversation. Those very opinions themselves had broached. Swift.
12. 13.To cause to begin or break out. [Obs.] Shak.
13. 14.(Masonry) To shape roughly, as a block of stone, by chiseling with a coarse tool. [Scot. & North of Eng.]
14. 15.To enlarge or dress (a hole), by using a broach. To broach to (Naut.), to incline suddenly to windward, so as to lay the sails aback, and expose the vessel to the danger of oversetting.