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.

Yeah.

At least his pelt keeps him warm.

But yeah, my dad is living proof of that one. His head has a ring of hair around it, like a monk’s. Hardly anything on his scalp.

When I was little, he would lounge around the house in his underwear…his chest was “Is he wearing a sweater?” hairy.