Tremulant is a term that is often used to describe something that is shaking or vibrating. There are a number of different synonyms that can be used to describe this sensation, including tremble, shiver, quiver, jitter, and quaver. Each of these words has a slightly different connotation and nuance, but all refer to the same basic idea: an involuntary shaking or vibrating movement. Whether you are trying to describe a quivering leaf on a tree or a shaking hand from nerves, these synonyms can help you to accurately capture the essence of the sensation of tremulant in your writing.