Bottled fuel (7)
I believe the answer is:
propane
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bottled fuel</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for propane that I've seen before include "Bottled fuel gas" , "Bottle gas" , "Type of gas" , "Gas used as fuel" , "gaseous fuel" .)