Word Study
deadpan
OXFORD DICTIONARY
deadpan, adj. & adv. with a face or manner totally lacking expression or emotion.
THESAURUS
deadpan
blank, cold-bloodedly, coldheartedly, coldly, dispassionately, empty, expressionless, fishy, glassy, heartlessly, impassive, in cold blood, inexpressive, poker-faced, spiritlessly, unemotionally, unexpressive, unfeelingly, unpassionately, vacant, with dry eyes, woodenFor further exploring for "deadpan" in Webster Dictionary Online