Acidly is an adverb that describes something done in a sharp or biting manner. There are several synonyms for this word, including sharply, acridly, cattily, sarcastically, tartly, and caustically. These words all describe a certain level of harshness or bitterness in speech or tone. For example, saying "she spoke acidly" could be replaced with "she spoke tartly," indicating that her words had a biting quality to them. Using synonyms can help add variety to your writing and communication while also more accurately capturing the intended tone or feeling.