Sidhe is a term that refers to a supernatural creature or a fairy-like creature in Irish mythology. There are many synonyms for the word "sidhe" used in various Irish legends. Some of these synonyms include Fey, Fae, Faerie, fair folk, fairy, and Tuatha De Danann. The sidhe or Tuatha De Danann is said to be mythical beings that possess magical powers and are known for their beauty and grace. The word Fae, which is often used in modern literature, translates to "fairy" but can also refer to the sidhe. Overall, the synonyms for sidhe offer different variations on the same mythical creature from Irish folklore.