Jellifying refers to the process of turning a liquid into a gel or a jelly-like substance. Some antonyms to this word could include liquefying, dissolving, melting, or thinning. Liquefying refers to the process of turning a solid into a liquid, while dissolving implies the process of mixing a substance in a liquid to the point of becoming a homogeneous solution. Melting is the process of warming up a solid until it becomes a liquid or a soft, malleable substance. Thinning refers to the process of reducing or diluting the viscosity of a liquid by adding a solvent. These are all opposite actions to jellifying.