Source : Free On-Line Dictionary of Computing

linear argument
     
         A function argument which is used exactly once by the
        function.
     
        If the argument is used at most once then it is safe to
        {inline} the function and replace the single occurrence of the
        formal parameter with the actual argument expression.  If the
        argument was used more than once this transformation would
        duplicate the argument expression, causing it to be evaluated
        more than once.
     
        If the argument is sure to be used at least once then it is
        safe to evaluate it in advance (see {strictness analysis})
        whereas if the argument was not used then this would waste
        work and might prevent the program from terminating.
     
        (1994-11-03)