Underground home allowed nursing staff to form community (10)
I believe the answer is:
settlement
'community' is the definition.
(settlement is a kind of community)
'underground home allowed nursing staff' is the wordplay.
'underground home' becomes 'sett' (home of a badger).
'allowed' becomes 'let' (I've seen this before).
'nursing' is an insertion indicator.
'staff' becomes 'men' (I've seen this in other clues).
'let' going around 'men' is 'lement'.
'sett'+'lement'='SETTLEMENT'
'to form' acts as a link.
(Other definitions for settlement that I've seen before include "Small outpost of families" , "Outpost; agreement" , "New community" , "kibbutz, say" , "village" .)