A type of puzzle (6)
I believe the answer is:
jigsaw
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a type of puzzle</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for jigsaw that I've seen before include "Sharp tool (for cutting puzzle into pieces?)" , "Puzzle - powered cutter" , "Puzzle fittingly completed" , "Problem with fitting in" , "Woodcutter" .)