Long to host current party game (9)
I believe the answer is:
paintball
'game' is the definition.
(I've seen this before)
'long to host current party' is the wordplay.
'long' becomes 'pant' (I've seen this before).
'to host' is an insertion indicator (inserted letters are hosted or welcomed).
'current' becomes 'I' (symbol for electric current).
'party' becomes 'ball' (ball is a kind of party).
'pant' going around 'i' is 'paint'.
'paint'+'ball'='PAINTBALL'
(Other definitions for paintball that I've seen before include "messy game" , "war game" , "Missile used in war games" , "simulated combat" .)