- A gold coloured metal that needs polishing often.
- The stuff that Cap Badges were made of.
- Slang for Pistol/Rifle Cartridges.
- Money (the old British threepenny piece was circa 60% brass).
- Nerve/cheek. As in: having the brass balls to haggle with a stall holder, get him to charge only 15 quid (he was asking 20), then give him a 20-quid note & ask for change. (True story.)
- Generic term for senior officers (used to be called "brasshats" owing to all the gold braid hanging off 'em).