Quick learner (6)
I believe the answer is:
sponge
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">quick learner</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 sponge that I've seen before include "Cadge; type of cake" , "Porous mass for wiping up" , "Sea animal often found in bathroom" , "that lives in the sea" , "Sea creature - cleanser - cake" .)