Act as host to amuse? (9)
I believe the answer is:
entertain
This clue is a double definition.
'act as host' is the first definition.
(I've seen this before)
'to amuse?' is the second definition.
(amusing is a kind of entertaining)
(Other definitions for entertain that I've seen before include "Provide amusement" , "Have a mind to - have a party" , "nurse" , "can be amusing" , "Have company" .)