n. A blank, expressionless face.n. A person, especially a performer, who has or assumes a blank expression.adj. Impassively matter-of-fact, as in style, behavior, or expression: deadpan delivery of the joke. ad. With a blank, expressionless face.v. To express in an impassive, matter-of-fact way.verb-intransitive. To express oneself in an impassive, matter-of-fact way.