Informally ironic (5)

I believe the answer is:

sarky

I'm a little stuck... Click here to teach me more about this clue!

'ironic' is the definition.
Both the answer and definition are adjectives.
Maybe there's a link between them I don't understand?

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Another definition for sarky that I've seen is " Mocking".)

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.