Grew into (6)
I believe the answer is:
became
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">grew into</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 became that I've seen before include "Began to be" , "Grew" , "Suited" , "Underwent a change" , "Got to be" .)