The definition of irony....
i·ro·ny ( P ) Pronunciation Key (r-n, r-)
n. pl. i·ro·nies
The use of words to express something different from and often opposite to their literal meaning.
An expression or utterance marked by a deliberate contrast between apparent and intended meaning.
A literary style employing such contrasts for humorous or rhetorical effect. See Synonyms at wit1.
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).
An occurrence, result, or circumstance notable for such incongruity. See Usage Note at ironic.
Dramatic irony.
Socratic irony.
But in reality it's when you are hitting on an older lady at a Thanksgiving party, and then you realize she a cougar tattoo'd on the small of her back. Sometimes life is just funny like that.