A wig is a head covering made from human or synthetic hair, typically worn as a fashion accessory or to conceal baldness. In the context of the clue "Costume department staple," it refers to a wig that is commonly used in theatrical productions or film and television to create different hairstyles and looks for characters.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Freak (out). Explanations are generated by AI and may be inaccurate.