Old English man, mann "human being, person (male or female); brave man, hero; servant, vassal," from Proto-Germanic *manwaz (cf. Old Saxon, Swedish, Dutch, Old High German man, German Mann, Old Norse maðr, Danish mand, Gothic manna "man"), from PIE root *man- (1) "man" (cf. Sanskrit manuh, Avestan manu-, Old Church Slavonic mozi, Russian muzh "man, male").
Plural men (German Männer) shows effects of i-mutation. Sometimes connected to root *men- "to think" (see