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