Tuck (thing)

(Forth:)

Another de-facto standard stack manipulation word, TUCK places a copy of the top word under the second word. You can define it as follows:

   : tuck ( x y -- y x y) swap over ;

TUCK is not a standard word; it's just so useful that everyone who needs it defines it thus, and calls it the same. Many implementations will also include it.

Compare NIP, DUP and OVER.