In a DO/LOOP or FOR/NEXT loop, causes the loop to exit. LEAVE should be used inside an IF...THEN block.

: TEST ( -- )
  10000 0 DO
    I .
    I 50 = IF ." EXITING EARLY" CR LEAVE THEN
  LOOP
;

In this example, the loop is supposed to execute 10,000 times. However, the loop exits when the index is equal to 50.

none