Very many soldiers (6)
I believe the answer is:
legion
This clue is a double definition.
'very many' is the first definition.
(I've seen this before)
'soldiers' is the second definition.
(I've seen this before)
(Other definitions for legion that I've seen before include "Roman military formation" , "Many soldiers" , "Military force - in Lego (anag)" , "Roman military body of men" , "Large unit of the old Roman army" .)