meltmelt /melt/ verb 
► melt
► melt if something solid melts, it changes to a liquid when it becomes warmer: In the spring the snow starts to melt. Melt two tablespoons of butter in a frying pan.
► thaw if something frozen thaws, it becomes warmer until all the ice is gone: The lake thawed in March. Thaw frozen meat in its packaging and then cook as soon as possible.
► defrost if frozen food defrosts, it gets warmer until it is not frozen anymore: The turkey needs to defrost overnight. You can defrost the meat in the microwave - it's quicker.
► dissolve if a solid dissolves in a liquid, it mixes with it and becomes part of it: Stir the water until all the sugar dissolves. Dissolve the aspirin tablet in a glass of water.