Snitched about oaf (3)

I believe the answer is:

nit

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'oaf' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.

'snitched about' is the wordplay.
'about' indicates a hidden word (the clue goes around or about the answer).
'NIT' is hidden within 'snitched'.

Can you help me to learn more?

(Other definitions for nit that I've seen before include "Stupid person; egg" , "Parasite's egg made of tin" , "Idiot, ass" , "Hair louse" , "Cause of much head-scratching" .)

I've seen this clue in The Mirror.

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