irony

The definition of irony is the use of words where the meaning is the opposite of their usual meaning or what is expected to happen.

(noun)

An example of irony is someone who talks a lot having nothing to say when asked a question.
An example of irony is a whaling ship being used to save marine animals after a tsunami.

See irony in Webster's New World College Dictionary

noun pl. ironies

1. a method of humorous or subtly sarcastic expression in which the intended meaning of the words is the direct opposite of their usual sense: the irony of calling a stupid plan “clever”
2. an instance of this
the contrast, as in a play, between what a character thinks the truth is, as revealed in a speech or action, and what an audience or reader knows the truth to be
often dramatic irony
a combination of circumstances or a result that is the opposite of what is or might be expected or considered appropriate: an irony that the firehouse burned
1. a cool, detached attitude of mind, characterized by recognition of the incongruities and complexities of experience
2. the expression of such an attitude in a literary work
the feigning of ignorance in argument: often called (after Socrates' use of this tactic in Plato's Dialogues)

Origin: Fr ironie < L ironia < Gr eirōneia < eirōn, dissembler in speech < eirein, to speak < IE base *wer-, to speak > word

adjective

of, like, or containing iron

See irony in American Heritage Dictionary 4

noun pl. i·ro·nies

a. The use of words to express something different from and often opposite to their literal meaning.
b. An expression or utterance marked by a deliberate contrast between apparent and intended meaning.
c. A literary style employing such contrasts for humorous or rhetorical effect. See Synonyms at wit¹.
a. Incongruity between what might be expected and what actually occurs: “Hyde noted the irony of Ireland's copying the nation she most hated” (Richard Kain).
b. An occurrence, result, or circumstance notable for such incongruity. See Usage Note at ironic.
Dramatic irony.
Socratic irony.