A coverb is a type of word that functions similar to a verb in a sentence but is defined as an adverbial or prepositional word that appears before or after the verb. In other words, it functions as a word that describes the verb, usually indicating the manner, time, or location of the action. Synonyms for coverb could include adverbial verb, preverb, particle verb, or it could be described as simply a type of adverb. Examples of coverbs include words like up, down, out, on, off, and over. These words add specific meaning to the main verb in the sentence and provide important context to the action described.