Arrangement for a rep sadly unable to move (9)
I believe the answer is:
paralysed
'unable to move' is the definition.
(I've seen this before)
'arrangement for a rep sadly' is the wordplay.
'arrangement for' indicates an anagram (I've seen this in other clues).
'a'+'rep'+'sadly'='arepsadly'
'arepsadly' is an anagram of 'PARALYSED'.
(Other definitions for paralysed that I've seen before include "brought to a standstill" , "Unable to move" , "Partly or wholly incapable of movement" , "Deprived of the power of movement" .)