sardonic

Sardonicism is "the quality or state of being sardonic; an instance of this; a sardonic remark." A sardonic action is one that is "disdainfully or skeptically humorous" or "derisively mocking." Also, when referring to laughter or a smile, it is "bitter, scornful, mocking." Hence, when referring to a person or a personal attribute, it is "[c]haracterized by or exhibiting bitterness, scorn or mockery."