Meaning

noun the act of killing yourself

noun a person who kills himself intentionally

originFirst attested in Thomas Browne's Religio Medici (1643) in noun sense 1, ostensibly from New Latin suīcīdium, from suī (genitive reflexive pronoun) + -cīdium (“act of killing or murder”), but often believed to have originated in English before entering Latin. Displaced native Middle English seolf-cwale from Old English selfcwalu (literally “self-slaughter”), after which suicide may have been…

Etymology from Wiktionary, CC BY-SA 3.0