Make-up of scoundrel beginning to get depressed (5)

I believe the answer is:

rouge

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'make-up' is the definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?

I can't explain the remainder of the clue.

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(Other definitions for rouge that I've seen before include "Cosmetic powder" , "Face-reddening cosmetic" , "struggle at Eton" , "Cheek colouring" , "Make-up item" .)

I've seen this clue in The Independent.

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