Decrescence is a term that is often used in music to describe a decrease in dynamics. In this case, some synonyms for decrescence might include words like diminuendo, which means to gradually get softer in volume. Another possible synonym for decrescence might be the term attenuate, which refers to the gradual lessening or weakening of a sound. Other possible synonyms for decrescence could include words like fade, soften, quiet, or mellow. Ultimately, the choice of synonym would depend on the specific context in which the term was being used, as well as the intended meaning and tone of the sentence or passage.