The truth about Capone (4)

I believe the answer is:

real

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'the truth' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.

'about capone' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'capone' becomes 'Al' (gangster Al Capone).
're'+'al'='REAL'

Can you help me to learn more?

(Other definitions for real that I've seen before include "Working together" , "Actual, not imagined" , "very American" , "Not imaginary, genuine" , "True" .)

I've seen this clue in the Evening Standard.

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