Rub shoulders with vagrant pinching new book (6)
I believe the answer is:
hobnob
'rub shoulders' is the definition.
(I've seen this before)
'vagrant pinching new book' is the wordplay.
'vagrant' becomes 'hobo' (I've seen this before).
'pinching' indicates putting letters inside (taking inside).
'new' becomes 'n'.
'book' becomes 'b'.
'hobo' enclosing 'n' is 'hobno'.
'hobno'+'b'='HOBNOB'
'with' is the link.
(Other definitions for hobnob that I've seen before include "Socialise informally" , "Associate socially with superiors" , "Associate on familiar terms" , "Socialise together, rub elbows with" , "Socialise familiarly" .)