Bruiser comes from bruise (Old English brȳsan, 'to crush, bruise', influenced by Old French bruisier, 'to break') + the agent suffix -er, denoting a heavy-handed fighter. The historical trail runs through brȳsan in Old English. Morphologically, bruiser is transparent: it draws on bruise (Old English brȳsan, 'to crush, bruise', influenced by Old French bruisier, 'to break') + the agent suffix -er, denoting a heavy-handed fighter. Used as a noun, bruiser now means "a tough, burly, aggressive person, especially a fighter", so the present definition can be read against the older forms and meanings. The same lexical family is also visible in related forms such as bruise and bruising. The result is a borrowed or transmitted form whose modern spelling carries a compact record of its route into English.