Actor Matthau
I believe the answer is:
walter
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">actor matthau</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for walter that I've seen before include "Elizabethan navigator" , "Sir . . . . . . Scott, famous Scottish poet and novelist of 'Ivanhoe' etc" , "Sir --- 23, novelist" , "Sir - Scott; - de la Mare" , "- de la Mare, English poet" .)