Very large copper can put in convict for bussing (10)

'bussing' is the definition.
('osculate' can be a synonym of 'buss')

'very large copper can put in convict' is the wordplay.
'very large' becomes 'os' (abbreviation for oversize).
'copper' becomes 'Cu' (Cu is the chemical symbol for copper).
'can' becomes 'tin' (both are metal containers).
'put in' means one lot of letters goes inside another (back).
'convict' becomes 'lag' (slang term for a prisoner).
'tin' inserted within 'lag' is 'lating'.
'os'+'cu'+'lating'='OSCULATING'

'for' is the link.