Outstanding underground network in having no leader (9)
I believe the answer is:
unsettled
'outstanding' is the definition.
(both can mean yet to be paid)
'underground network in having no leader' is the wordplay.
'underground network' becomes 'sett' (a sett is an animal burrow).
'in' indicates putting letters inside.
'having no leader' becomes 'unled' (not led by anyone).
'sett' inserted within 'unled' is 'UNSETTLED'.
(Other definitions for unsettled that I've seen before include "Devoid of colonists" , "Not fine" , "Missing work by composer, perhaps" , "lawless" , "outstanding" .)