Brainy sort (4)
I believe the answer is:
nerd
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">brainy sort</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 nerd that I've seen before include "Sort of chap" , "Feeble person (sl.)" , "Boringly studious person" , "In slang, a foolish or uninteresting person" , "Foolish or annoying person" .)