Presented a rear view across a river that's cut off (8)
I believe the answer is:
marooned
'cut off' is the definition.
(someone marooned is cut off from society)
'presented a rear view across a river' is the wordplay.
'presented a rear view' becomes 'mooned' (to moon is to show your buttocks).
'across' is an insertion indicator.
'river' becomes 'r' (abbreviation).
'a'+'r'='ar'
'mooned' going around 'ar' is 'MAROONED'.
'that's' acts as a link.
(Other definitions for marooned that I've seen before include "Left stranded with little hope of rescue" , "Abandoned on island" , "Left high and dry" , "Abandoned like Robinson Crusoe" , "Me on road (anag.)" .)