Source : Free On-Line Dictionary of Computing

unwind-protect
     
        ({MIT}) A {Lisp} operator which evaluates an expression and
        then, even if that expression causes a {non-local exit},
        evaluates zero or more other expressions.  This can be used to
        ensure that essential "clean-up" operations are performed even
        in the presence of errors.
     
        [{Jargon File}]
     
        (1994-11-03)