3.21 Leaving definitions or loops

EXIT exits the current definition right away. For every counted loop that is left in this way, an UNLOOP has to be performed before the EXIT:

: ...
 ... u+do
   ... if
     ... unloop exit
   endif
   ...
 loop
 ... ;

LEAVE leaves the innermost counted loop right away:

: ...
 ... u+do
   ... if
     ... leave
   endif
   ...
 loop
 ... ;

Reference: Calls and returns, Counted Loops.