Bill loses third of money, having soldiers to equip (8)
I believe the answer is:
accoutre
'equip' is the definition.
(accoutring is a kind of equiping)
'bill loses third' is the wordplay.
'bill' becomes 'acc'.
'loses third' becomes 'outre' (I am not sure about this - if you are sure you should believe this answer much more).
'acc'+'outre'='ACCOUTRE'
'of money having soldiers to' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
(Other definitions for accoutre that I've seen before include "get ready for war" , "Clothe in something noticeable or impressive" , "Attire" , "Furnish" , "Deck" .)