There are many different words that can be used to describe a sudden thought. One word that is commonly used is "epiphany," which refers to a sudden realization or insight. Another synonym for a sudden thought is "revelation," which suggests something that has been uncovered or discovered. "Inspiration" is another word that can be used to describe a sudden thought, especially one that is creative or innovative. Other words that can be used to describe sudden thoughts include "flash," "brainwave," "idea," and "thought burst." Regardless of the specific term used, a sudden thought is a powerful and often transformative experience that can lead to new ideas and insights.