They entertain armies (5)
I believe the answer is:
hosts
I believe this clue is a double definition.
'they entertain' is the first definition.
(I've seen this before)
'armies' is the second definition.
(host is a kind of army)
(Other definitions for hosts that I've seen before include "Great numbers of party-givers" , "People who entertain" , "welcomers of guests" , "Landlords" , "those entertaining guests" .)