Nasty person curate had to endure? Not entirely (3,3)

I believe the answer is:

bad egg

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'nasty person' is the definition.
(a bad egg is an unpleasant person)

I can't explain the rest of the clue.

(Other definitions for bad egg that I've seen before include "Worthless person" , "A real stinker?" , "Villain" , "Rotten scoundrel?" , "Worthless individual" .)

I've seen this clue in The Guardian.

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