A cosh pocket is a long internal pocket running in a mid-axillary line (i.e. a line from the middle of the armpit). The said pocket is for concealing a handy weapon, known as a cosh (usually made of metal covered by a softer material). To ask a man if he possesses a coat with a cosh pocket is to ask him whether he is "unclubbable".
Thanks, old bean. A cosh pocket I meant indeed. Though I wouldn't think to suggest that in asking the question, I was implying something else. Still I would be curious if anyone had ever outfitted his coat with a pocket for cosh, firearm or what have you. Perhaps one could widen the thread to ask if one had asked his tailor for any pocket to hold any item not out-of-the-ordinary. When I was in New York, a colleague of a rather paranoid persuasion had a tailor sew a pocket to stash his .25 calibre fire-arm. A bit much I thought. But NY wasn't as friendly then. As for cash pockets: love 'em. I usually get either off-the-peg or MTM trousers with them. The photos above look esp. good. Pip pip, H.