Pained expression (7)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pained expression</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for grimace that I've seen before include "Facial expression showing disgust, wry humour etc" , "Pained expression" , "Expression of pain or disgust" , "(Make) a wry face" , "Glower" .)