Any of various types of nails with large flat heads designed to fasten sheet metal to wood, fasten clouts to axletrees, etc., often clinched.
A stationery fastening device made of thin, soft metal, with a round head and a flat, split shank, which is spread after insertion in a hole in a stack of pages, in much the same way as a cotter pin or a split rivet.
Any similar stationery fastening device.