Is “Irony” a Scrabble word?

1.A statement that, when taken in context, may actually mean something different from, or the opposite of, what is written literally; the use of words expressing something other than their literal intention, often in a humorous context.

2.Dramatic irony: a theatrical effect in which the meaning of a situation, or some incongruity in the plot, is understood by the audience, but not by the characters in the play.

3.Ignorance feigned for the purpose of confounding or provoking an antagonist; Socratic irony.