Shrewd tongue is a phrase that is commonly used to describe someone who is extremely clever and quick-witted when it comes to using language to their advantage. There are a variety of different synonyms that can be used to describe this same trait, including sharp-tongued, eloquent, articulate, quick-witted, clever, cunning, and astute. These words all convey a sense of intelligence and skill when it comes to using language, and they can be used to describe individuals who are able to express themselves in a very effective and persuasive manner. Whether you are looking for a way to describe someone you admire or simply want to expand your vocabulary, these synonyms will definitely come in handy.