Feed the Flames is an idiom that means to increase the intensity of something, usually a situation or emotion. The crossword solutions for this term are STOKE and FUEL. To STOKE something means to add FUEL to it in order to increase its intensity, while to FUEL something means to provide it with the necessary energy to keep it going. Therefore, Feed the Flames can be interpreted as adding FUEL and energy to a situation or emotion in order to make it more intense.