Proctor's call (4)
I believe the answer is:
time
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">proctor's call</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for time that I've seen before include "It's measured by watch or clock" , "Duration; tempo" , "Rhythm" , "Spell" , "Prison sentence; occasion" .)