"A-tremble" is a word that is used to describe a state of shaking or trembling. The word can be used to describe both physical and emotional states. Some synonyms for "a-tremble" include trembling, shaking, shivering, quivering, quaking, and quavering. These words can be used interchangeably to describe a state of fear, nervousness, cold, or physical weakness. It can also be used to describe objects that are shaking or vibrating. The use of synonyms can help to add depth and variety to writing, making it more interesting and engaging for readers.