For fun, one chills G&T, welcoming entertainer with precipitation (5,5)
I believe the answer is:
ghost train
'for fun one chills' is the definition.
I know nothing about this answer so I can't judge whether this works.
'gt welcoming entertainer with precipitation' is the wordplay.
'welcoming' is an insertion indicator (in sense of 'inviting in').
'entertainer' becomes 'host' (person hosting or entertaining guests).
'with' means one lot of letters go next to another.
'precipitation' becomes 'rain' (rain is a kind of precipitation).
'gt' going around 'host' is 'ghostt'.
'ghostt'+'rain'='GHOST-TRAIN'
Can you help me to learn more?
(Other definitions for ghost train that I've seen before include "scary ride" , "Spooky ride" , "funfair ride" , "Fairground attraction" .)