Source : WordNet®

prefix notation
     n : a parenthesis-free notation for forming mathematical
         expressions in which each operator precedes its operands
         [syn: {Lukasiewicz notation}, {Polish notation}]

Source : Free On-Line Dictionary of Computing

prefix notation
     
         (Or "prefix syntax") One of the possible orderings
        of {functions} and {operands}: in prefix notation the function
        precedes all its operands.  For example, what may normally be
        written as "1+2" becomes "(+ 1 2)".  A few languages (e.g.,
        {lisp}) have strictly prefix syntax, many more employ prefix
        notation in combination with {infix notation}.
     
        Compare: {postfix notation}.
     
        (2001-02-14)