Amorphous shape (4)
I believe the answer is:
blob
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">amorphous shape</span>' is the definition.<br/ ><span class="explanation-format__explanation">(blob is a kind of amorphous shape)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for blob that I've seen before include "Drop of thick liquid or viscous substance" , "Indistinct object" , "Something small, soft and round" , "Small piece signifying nothing" , "Mark signifying nothing" .)