Popular goalie entertains northern host (9)
I believe the answer is:
innkeeper
'host' is the definition.
('innkeeper' can be a synonym of 'host')
'popular goalie entertains northern' is the wordplay.
'popular' becomes 'in'.
'goalie' becomes 'keeper' (I've seen this before).
'entertains' means one lot of letters goes inside another.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'in'+'keeper'='inkeeper'
'inkeeper' placed around 'n' is 'INNKEEPER'.
(Other definitions for innkeeper that I've seen before include "Mine host" , "Pub runner" , "Job" , "Publican" , "Pub landlord" .)