Strangely amusing (5)
I believe the answer is:
droll
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strangely amusing</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 droll that I've seen before include "rum" , "Drily amusing" , "Large amount (of matter)" , "Mildly amusing" , "Quaintly amusing" .)