Fool with identical twin dismisses nice lad (6)

I believe the answer is:

nitwit

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'dismisses nice lad' is the definition.
I can't judge whether this defines the answer.

'fool with identical twin' is the wordplay.
'fool' becomes 'nit' (I've seen this before).
'with identical twin' becomes 'wit' (this might be a standard abbreviation of which I'm unaware).
'nit'+'wit'='NITWIT'

Can you help me to learn more?

(Other definitions for nitwit that I've seen before include "Fool, idiot" , "Informally a stupid person, like funny flea?" , "Foolish person like humorous louse" , "'Foolish, silly person (6)'" , "Simpleton" .)

I've seen this clue in the Irish Times.

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