ironical

ironic, ironical, ironically

For the adjective, choice between ironic and ironical seems to be determined largely by sentence rhythm. Both words properly mean ‘of the nature of irony’, i.e. implying the opposite of what is literally or normally meant by a word, look, etc.:

• She gave an ironical laugh as she looked at Guy —Olivia Manning, 1977.

In this sentence, ironical shows that the laugh was marking something other than the usual humour. Both words, however, are now increasingly used to mean simply ‘odd, strange, paradoxical’, and the same is true of the corresponding adverb ironically:

• It is paradoxical, ‘ironical’ as people say today, that the constitution should bestow this power on someone who laments constitutionitis in others —Observer, 1987

• It is ironic that such a beautiful orderly house should be the setting of our messy little farce —S. Mason, 1990

• Ironically the bombing of London was a blessing to the youthful generations that followed —I. &. P. Opie, 1969

• Ironically, many modern writers have been nihilistic toward modern culture —Dissent, AmE 2004.

These uses, which are well established despite frequent criticism of them, perhaps contain an echo of the concept of dramatic irony, in which an audience is made aware of an act or circumstance that affects the action on stage (or screen) in a way that is unknown to one or more of the participants in the drama.