A nut with rounded extensions projecting past the nut's opening. A cotter pin is inserted through a hole in the bolt and bent around the castle nut's projections to lock the nut in place.

The seed of the areca palm (not a true nut but a drupe), chewed as a mild stimulant.

plural of nut roll

A pastry of yeast bread with one or more fillings, found in the United States and in Central European cuisines.

(intransitive, slang) To show courage and hide one's apprehension.

a form of boulder opal from Yowah, Australia.

(transitive, Australia, New Zealand, informal) To find a solution (for something), especially in a group discussion; also, to work out the finer details (of something).

(intransitive, US, informal) To become crazy, especially with rage.

The macadamia nut.

plural of nut job