Finding new home for unfortunate neighbours losing billions (9)
I believe the answer is:
rehousing
'finding new home for' is the definition.
'unfortunate neighbours losing billions' is the wordplay.
'unfortunate' indicates an anagram.
'losing' suggests deleting specific letters.
'billions' becomes 'b'.
'neighbours' with 'b' taken out is 'neighours'.
'neighours' is an anagram of 'REHOUSING'.
(Other definitions for rehousing that I've seen before include "Moving" , "new living quarters?" , "Giving residence to elsewhere" .)