Subtle humour cryptically “Fey”? (5)

I believe the answer is:

irony

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

'subtle humour' is the definition.
(I've seen this before)

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

(Other definitions for irony that I've seen before include "Might this be dramatic" , "Sarcastic use of praise" , "Paradoxical sarcasm" , "Satirical speech form" , "sarcastic wit" .)

I've seen this clue in The Times.

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