bruise
Word family
Synonym discussion
Sense: noun/1
For an everyday dark mark under the skin, bruise is the normal word. Contusion is the medical term, so it appears more often in hospital notes than in daily conversation. A cut is different because the skin opens, while a scratch is only light surface damage from rubbing or something sharp. Swelling often comes with a bruise, but it names the area getting bigger, not the dark colour itself. For fruit, bruise also sounds natural, while damage is broader and less exact. You can say 'I have a bruise on my knee,' but a doctor may write 'knee contusion' in a report.
Common collocations
Etymology
Bruise goes back to Old English brysan, a verb meaning 'crush or injure with a blow'. In Middle English it was strengthened by a related Old French verb, bruisier, meaning 'break'. The noun came later from the verb, so the word first described the act of hitting or crushing and then the dark mark left behind.