Can't rude jockeys perform with some restraint? (8)

I believe the answer is:

underact

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'perform with some restraint?' is the definition.
I can't tell whether this definition defines the answer.

'can't rude jockeys' is the wordplay.
'jockeys' is an anagram indicator.
'cant'+'rude'='cantrude'
'cantrude' is an anagram of 'UNDERACT'.

Can you help me to learn more?

(Other definitions for underact that I've seen before include "Deliver role in a restrained manner" , "Perform impassively" , "Minimise part played" , "put little into role" , "Play down for effect" .)

I've seen this clue in The Times.

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