Nobs, very loud, turned up drunk outside (5)
I believe the answer is:
toffs
'nobs' is the definition.
('toff' can be a synonym of 'nob')
'loud turned up drunk outside' is the wordplay.
'loud' becomes 'ff' (short for fortissimo - 'very loud' in music).
'turned up' says the letters should be written backwards.
'drunk' becomes 'sot' (sot can mean a drunken person).
'outside' means one lot of letters goes inside another (some letters go outside others).
'sot' reversed gives 'tos'.
'ff' going into 'tos' is 'TOFFS'.
'very' is the link.
(Other definitions for toffs that I've seen before include "Posh folk" , "Posh gents" , "Nobs" , "Posh blokes" , "aristos" .)