Host, master of ceremonies (7)
I believe the answer is:
compere
I believe this clue is a double definition.
'host' is the first definition.
(host of an event)
'master of ceremonies' is the second definition.
(compere is a kind of master of ceremonies)
(Other definitions for compere that I've seen before include "TV presenter?" , "host show" , "(Male) show introducer" , "M.C." , "Master of ceremonies" .)