Police trainee (5)
I believe the answer is:
cadet
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">police trainee</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for cadet that I've seen before include "not the heir" , "Officer in training" , "One taking instructions" , "junior role" , "Armed services trainee" .)