Fills with air (8)
I believe the answer is:
inflates
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fills with air</span>' is the definition.<br/ ><span class="explanation-format__explanation">('inflate' can be a synonym of 'fill with air')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for inflates that I've seen before include "Blows up" , "Exaggerates" .)