From Longman Dictionary of Contemporary Englishbrass knucklesˌbrass ˈknuckles noun [plural] American English PMWa set of connected metal rings worn over a person’s fingers, used as a weapon SYN knuckle-duster British English
Examples from the Corpus
brass knuckles• The writer was wearing a bulletproof vest and had brass knuckles and chemical repellent in other pockets.• William Joyce presented the clenched fist in an armour of brass knuckles.• You know and then we were getting these whole boxes of brass knuckles or whatever.• Its grip consisted of brass knuckles, was a chain of rings through which Weary slipped his stubby fingers. 