Bubbles (4)
I believe the answer is:
foam
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bubbles</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for foam that I've seen before include "Mass of small bubbles" , "Fizz, froth" , "Froth or spume" , "Sea froth" , "Lather, froth" .)