Perishes is a word that typically refers to the act of dying or ceasing to exist. There are a few different synonyms that can be used to describe this concept. For example, the word "expires" is often used to refer to something that has come to an end or is no longer viable. "Fades away" is another common phrase that can be used to describe the process of something gradually disappearing or losing its vitality. Other synonyms for "perishes" might include terms like "vanishes", "disappears", "ceases to be", "dies out", or "fades into oblivion". Ultimately, the choice of synonym will depend on the context in which the word is being used and the precise shade of meaning that is desired.