- containing or producing many nuts
- having a nutlike flavor
- Slangoften nut′sy
- enthusiastic, often to excess
- odd, foolish, crazy, etc.
(comparative nuttier, superlative nuttiest)
In sense “insane", similar to nuts, but more limited and somewhat milder: nutty means “eccentric, insane", while “nuts" can mean either “insane" or “enthused, agitated" (“the crowd went nuts"), for which “nutty" is not used: *“the crowd went nutty".
nut +"Ž -y