Is it ensure, insure, or assure?
"pointed instrument," c.1300, from Old French broche (12c.) "spit for roasting, awl, point end, top," from Vulgar Latin *brocca "pointed tool," noun use of fem. of Latin adjective broccus "projecting, pointed" (used especially of teeth), perhaps of Gaulish origin (cf. Gaelic brog "awl").
"pierce," early 14c., from the same source as broach (n.). Meaning "begin to talk about" is 1570s, a figurative use with suggestions of "broaching" a cask or of spurring into action (cf. Old French brochier, 12c., "to spur," also "to penetrate sexually"). Related: Broached broaching.
A dental instrument for removing the pulp of a tooth or exploring its canal.