Cerebral (6)
I believe the answer is:
brainy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cerebral</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for brainy that I've seen before include "Clever, got lots of grey matter" , "Showing intelligence" , "smart?" , "Bright" , "Highly intelligent" .)