Socialise (6)
I believe the answer is:
hobnob
'socialise' is the definition.
(I know that hobnob is a more specific form of the action socialise)
This is all the clue.
(Other definitions for hobnob that I've seen before include "Feasible" , "Socialise (especially with posher people)" , "Spend time chatting to a VIP?" , "Socialise together, rub elbows with" , "random" .)