They're "inflatable" (4)
I believe the answer is:
egos
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">they're inflatable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for egos that I've seen before include "Lots of self-esteem" , "People's personal pride - the parts of them that are conscious" , "Self-images" , "feelings of self-importance" .)