"Brooch" also rhymes with "coach" most of the time in America. I always felt that those who rhyme it with "pooch" are perhaps not familiar with the word and are simply trying to pronounce it as it is spelled. However, William Safire, in a 1998 New York Times article, had a different take:
"The story begins with the Middle English word broche, from the Latin brocca, spike, ''with the o pronounced as in Oh, yeah? ''As a noun, broche meant a tapering pointed instrument, ''like a spear, a bodkin or a spit on which to roast meat, and centuries later, a chisel used by masons or a pick used by dentists. That meaning exists today in the French en brochette, with the skewer sticking through chunks of meat and onion and tomato. (Don't try to get it off with your fork or you'll splatter the bed of rice all over the table; let the waiter do it.)
"As a verb, to broach carried forward that meaning of turning. Ships broach to when they turn broadside to wind or waves and thereby risk capsizing. Vintners tap a cask by broaching it, or enlarging a hole with a boring-bit also called a broach. That digging into ''sense led to the current major meaning, to introduce, to give vent to, to utter, ''which is why we have been able to broach this subject today.
"While this was happening to the verb, the noun rooted in broche was developing in the jewelry business. Send hire letters, tokens, brooches, rynges, ''advised Chaucer's narrator in 1385, in ''The Legend of Good Women,'' possibly against his amanuensis' better judgment, with the brooch denoting a pin (the original spike) attached to an ornament or jewel to form a clasp. Today, it is often synonymous with pin, ''but retains a special meaning of an ornamental device intended to clasp two garments, or sections of a garment, together -- or at least seeming to.
"Note the way the word broke into two spellings: the verb broach, meaning to open up, introduce, address, ''and the noun brooch, meaning an ornamental pin sticking through a garment.''
"To me, that spelling split is a signal to pronounce the verb broach to rhyme with coach, and to pronounce the noun brooch to rhyme with pooch. (Nice dog, Buddy.)
"Many respected dictionaries do not agree with me on this. They hold fast to the oach ''pronunciation for both verb and noun. Be patient; they'll catch up."