← BackshareGuessunplayful/ʌnˈpleɪfəl/adjectiveNot playful; serious, solemn, or lacking a sense of fun.The puppy seemed unusually unplayful and just wanted to sleep.His unplayful attitude at the party surprised everyone who knew him.The teacher's unplayful tone made the students nervous.SynonymssolemnseriousAntonymsplayful