Ignorant get behind beaten (9)
I believe the answer is:
benighted
'ignorant' is the definition.
(I've seen this before)
'get behind beaten' is the wordplay.
'beaten' indicates an anagram.
'get'+'behind'='getbehind'
'getbehind' is an anagram of 'BENIGHTED'.
(Other definitions for benighted that I've seen before include "Get behind (anag) - being ignorant" , "Ignorant; caught in dark" .)