Nick, old boy and VIP (5)
I believe the answer is:
nabob
'vip' is the definition.
(I've seen this before)
'nick old boy' is the wordplay.
'nick' becomes 'nab' (both can mean steal).
'old boy' becomes 'OB' (abbreviation for a private school 'old boy').
'nab'+'ob'='NABOB'
'and' is the link.
(Other definitions for nabob that I've seen before include "moneybags" , "Powerful man" , "Magnate; formerly one with Eastern wealth" , "Person of conspicuous wealth or high status" , "Rich British merchant in India" .)