Become fuzzy (4)
I believe the answer is:
blur
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">become fuzzy</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 blur that I've seen before include "Make vague" , "Out-of-focus image" , "British rock group" , "Obscure; smudge" , "Britpop band - indistinct vision" .)