Scandal, at first informal chat, going about concerning Saint Nicholas? (7)

'nicholas?' is the definition.
(Nicholas Parsons was a radio and TV presenter)

'scandal at first informal chat going about concerning saint' is the wordplay.
'at first' suggests taking the first letters.
'informal chat' becomes 'rap' (rap can informally mean to chat or talk).
'going about' is a reversal indicator (letters go about or around).
'concerning' becomes 'on' (both can mean 'in relation to').
'saint' becomes 's'.
The first letter of 'scandal' is 's'.
's'+'rap'='srap'
'srap' in reverse letter order is 'pars'.
'pars'+'on'+'s'='PARSONS'