Originally gender-neutral in Old English, meaning 'person' — males were 'wer' (as in werewolf), females were 'wif.'
An adult male human being; also, historically, a human being of either sex.
From Old English 'mann' (human being, person — originally gender-neutral in Old English, applying to men and women alike), from Proto-Germanic *mann-, from PIE *man- (man, human being) or possibly related to PIE *men- (to think — man as the thinking being). In Old English, the generic human was 'mann'; a male was 'wer' (cognate with Latin 'vir', as in 'virile') or 'wǣpnedmann' (weapon-person); a female was 'wīf' (→ 'wife') or 'wīfmann' (woman, literally female-person). The narrowing of 'man' to the male sex is a
In Old English law, killing a 'mann' (any person) was 'mannslæht' — manslaughter. The word was gender-neutral, so 'manslaughter' literally meant 'person-slaying,' not specifically the killing of a male. The gendered meaning of 'man' only fully displaced the neutral meaning in the late medieval period.