A large number (4)
(Other definitions for host that I've seen before include "Crowd-entertainer" , "One entertaining, large number" , "Pub landlord" , "Entertainer of guests" , "Party-giver" .)
'a large number' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for many that I've seen before include "Multitudinous" , "multitude" , "A great number" , "Several" , "Lots" .)