Fuel gas (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fuel gas</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 butane that I've seen before include "Bottled gas used as a fuel" , "Flammable gas in petroleum" , "Lighter fuel" , "Inflammable gas produced from petrol" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fuel gas</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for methane that I've seen before include "Flammable gas, CH4" , "Get fuel" , "contributor to global warming" , "Naturally occurring flammable gas" , "Marsh gas - the name (anag)" .)