Associate goblin with aristocrat (6)
I believe the answer is:
hobnob
'associate' is the definition.
(to hobnob with people is to associate with them)
'goblin with aristocrat' is the wordplay.
'goblin' becomes 'hob' (synonyms).
'with' says to put letters next to each other.
'aristocrat' becomes 'nob' (I've seen this in other clues).
'hob'+'nob'='HOBNOB'
(Other definitions for hobnob that I've seen before include "Talk informally" , "Feasible" , "Associate socially with superiors" , "Socialise (especially with posher people)" , "Associate informally" .)