The term "most congealed" refers to a substance that has thickened or solidified due to cold or other factors. Antonyms for this term generally involve words that describe substances that are less dense, more fluid, or less solid. Some possible antonyms for "most congealed" might include words like liquid, runny, flowing, fluid, loose, watery, or thin. These words suggest a substance that is more easily poured or spread and might be used to describe things like liquids, sauces, or soups. Other possible antonyms might include words like soft, malleable, pliable, or supple, which suggest substances that are more pliant, flexible, or yielding.