From Old English 'hnutu,' from PIE *kneu- (nut) — a basic food word traceable to the earliest Indo-European.
A hard-shelled fruit of certain trees; an informal word for a crazy person.
From Old English 'hnutu' meaning 'nut,' from Proto-Germanic *hnut-, from PIE *kneu- (nut). The 'h' was once pronounced. The 'crazy person' sense appeared in the 1900s — 'off one's nut' (off one's head). Key roots: *kneu- (PIE: "nut").