Contradiction in terms (7)
I believe the answer is:
paradox
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">contradiction in terms</span>' is the definition.<br/ ><span class="explanation-format__explanation">(paradox is a kind of contradiction in terms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for paradox that I've seen before include "Seeming contradiction" , "Seemingly sound, though self-contradictory, statement" , "Absurd or self-contradictory statement" , "Seemingly absurd statement that may be true" , "Statement that seems contradictory but expresses truth" .)