ironic, ironical -- (characterized by often poignant difference or incongruity between what is expected and what actually is; "madness, an ironic fate for such a clear thinker"; "it was ironical that the well-planned scheme failed so completely")
dry, ironic, ironical, wry -- (humorously sarcastic or mocking; "dry humor"; "an ironic remark often conveys an intended meaning obliquely"; "an ironic novel"; "an ironical smile"; "with a wry Scottish wit")