The crazy pair figure to be quick (5)

I believe the answer is:

rapid

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'be quick' is the definition.
(synonyms)

'the crazy pair figure' is the wordplay.
I cannot really see how this works, but
an anagram of 'pair' is 'rapi' which is within the answer.
A single letter 'd' remains which might be clued in a way I don't see.
This explanation may well be incorrect...

'to' acts as a link.

Can you help me to learn more?

(Other definitions for rapid that I've seen before include "Speedy (5)" , "Happening quickly" , "Flying" , "Quickly accomplished" , "Fleet, swift" .)

I've seen this clue in the Evening Standard.

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