Noun irony has 3 senses
  1. sarcasm, irony, satire, caustic remark - witty language used to convey insults or scorn; "he used sarcasm to upset his opponent"; "irony is wasted on the stupid"; "Satire is a sort of glass, wherein beholders do generally discover everybody's face but their own"--Johathan Swift
    --1 is a kind of wit, humor, humour, witticism, wittiness
  2. irony - incongruity between what might be expected and what actually occurs; "the irony of Ireland's copying the nation she most hated"
    --2 is a kind of
    incongruity, incongruousness
    --2 has particulars: Socratic irony
  3. irony - a trope that involves incongruity between what is expected and what occurs
    --3 is a kind of
    trope, figure of speech, figure, image
    --3 has part: antiphrasis
    --3 has particulars: dramatic irony