Chit-chat (5,4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">chit-chat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that chit-chat can be written as small talk)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for small talk that I've seen before include "Polite conversation on trivial matters" , "Unimportant prattle" , "Social chat on unimportant matters" , "Light conversation" , "chattering" .)
(Another definition for idle talk that I've seen is " It's foolish to say".)
(Other definitions for gas that I've seen before include "Form of fossil fuel" , "Talk excessively" , "THIRD PART OF 23" , "Talk idly; fuel" , "Nitrogen maybe" .)