The antonyms for the word "more decalescent" could include "cooler," "colder," "chilled," "frigid," and "icy." These words connote a decrease in temperature and a stark contrast to the original meaning of "more decalescent," which refers to an increase in heat or warmth. Alternatively, words like "blunt," "dull," or "lifeless" could also serve as antonyms for "more decalescent" in a figurative sense, representing a lack of passion or energy. It's important to consider the context in which the word is used when determining appropriate antonyms, to ensure that the intended contrast is effectively conveyed.