High ones are fun (5)

I believe the answer is:

jinks

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

This clue might be a double definition.

'high ones are' is the first definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.

'fun' is the second definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

Can you help me to learn more?

(Another definition for jinks that I've seen is " Dodges".)

I've seen this clue in the Evening Standard.

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