Nut verb. (mostly in the form "nutting") To gather nuts. Nut verb. To hit deliberately with the head; to headbutt. Nut verb. To ejaculate. Nut noun. The fruit of certain trees and shrubs (as of the almond, walnut, hickory, beech, filbert, etc.), consisting of a hard and indehiscent shell inclosing a kernel. Nut noun.