Letter puzzle (7)
I believe the answer is:
anagram
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">letter puzzle</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 anagram that I've seen before include "Jumbling of letters" , "Word with rearrangeable letters" , "1d for instance" , "Word that rearranges another's letters" , "Word created from other word" .)