A deadpan expression is a facial expression that shows no emotion or reaction to a situation. Some synonyms for deadpan expression include blank expression, poker face, stone face, impassive expression, and straight face. These expressions are commonly used to hide one's true feelings or to appear serious and professional in certain situations. Deadpan expressions are often associated with humor, especially in stand-up comedy, where a comedian will use deadpan delivery to deliver a punchline for comedic effect. However, in everyday life, a deadpan expression can also indicate disinterest, boredom, or a lack of enthusiasm.