A less than engaging witticism (3)

I believe the answer is:

gag

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

'witticism' is the definition.
(gag is a kind of witticism)

'a less than engaging' is the wordplay.
'GAG' is hidden in amongst the letters.
But, I'm uncertain how the hidden word is indicated.

Can you help me to learn more?

(Other definitions for gag that I've seen before include "Muffle with slang joke" , "Muzzle in palindrome form" , "Censor" , "Muzzle or silence" , "Joke or muffler - a palindrome" .)

I've seen this clue in the Evening Standard.

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