Yawned (5)
I believe the answer is:
gaped
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">yawned</span>' is the definition.<br/ ><span class="explanation-format__explanation">('gape' can be a synonym of 'yawn')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for gaped that I've seen before include "shown astonishment" , "Opened mouth wide" , "Stared open-mouthed - yawned" , "Was yawning" , "Looked stunned" .)