Monkey or ape scratching companion (3)

I believe the answer is:

imp

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'monkey' is the definition.
(I know that monkey can be written as imp)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for imp that I've seen before include "Small devil or sprite" , "Sprite; add feathers to" , "Mischievous monkey" , "Evil spirit" , "Goblin" .)

I've seen this clue in The Times.

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