Learnt (5)
I believe the answer is:
heard
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">learnt</span>' is the definition.<br/ ><span class="explanation-format__explanation">('hear' can be a synonym of 'learn')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for heard that I've seen before include "Picked up by the ears?" , "Gave ear to" , "Received aurally" , "Perceived sound" , "Was told of" .)