Party get-together (6)
I believe the answer is:
caucus
'party get-together' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for caucus that I've seen before include "(US) party meeting" , "Meeting to select a political candidate in the US" , "Political gathering to select a candidate, US-style" , "Small dominant inner group" , "Policy meeting" .)