Change in form (6)
I believe the answer is:
mutate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">change in form</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 mutate that I've seen before include "Gradually change form" , "Undergo alteration in form" , "Change genetically" , "(In genetics) change" , "Undergo cellular change" .)