The word nuts is an adjective. Nuts means (1) informal or slang terms for mentally irregular.
Nuts is also a plural noun that means, in its singular form, (1) a fruit composed of an inedible hard shell plus an edible seed or kernel, (2) a piece of metal or other material with a threaded hole through it.
The following articles and web pages elaborate on the word nuts.
A cellophane-wrapped and ribbon-tied gourmet gift basket is ready to present to a client. Included in the basket are sausages and cheese, crackers and nuts, and chips and dip.