Longman Dictionary of Contemporary English - fuel

~1 n 1 a substance such as coal, gas, or oil that can be burned to produce heat or energy  (Don't leave the engine switched on. It wastes fuel. | Coal is one of the cheapest fuels.) 2 something that makes someone's anger, hatred etc worse  (fuel to sth)  (His behaviour was only fuel to her jealousy.) 3 add fuel to the fire/flames to make a situation a lot worse than it was already ~2 v past tense fuelled BrE, fueled AmE 1 to make a situation worse or make someone's feelings stronger  (The attempts to stop the strike only fuelled the workers' resentment.) 2 to put oil, petrol etc in a vehicle 3 also fuel up if a vehicle fuels up, fuel is put into it  (It's amazing that some planes can fuel up in mid air.)