Using air (9)
I believe the answer is:
pneumatic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">using air</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 pneumatic that I've seen before include "Air-powered" , "Concerned with air, gases or wind" , "form of drill?" , "Operated by pressurised gas" , "Inflated with air" .)