Having a cross section in the form of an equilateral triangle; said especially of a kind of file.

(obsolete) The finest and most costly kind of velvet, with a fine, thick pile.

(American football) The situation where a team is forced to punt the football without having made any first downs.

plural of three-and-out

Having three forks or prongs.

Alternative form of three of a kind

(baseball slang) A triple.

plural of three-bagger

(aviation) a confirmation given by the pilots that the landing gear has gone down successfully and has locked.

Less common spelling of three-quarters