Perplex with support for reversion to an earlier type (9)
I believe the answer is:
throwback
'reversion to an earlier type' is the definition.
(I've seen this before)
'perplex with support' is the wordplay.
'perplex' becomes 'throw' ('throw' can be a synonym of 'perplex').
'with' means one lot of letters go next to another.
'support' becomes 'back' (back is a kind of support).
'throw'+'back'='THROWBACK'
'for' acts as a link.
(Other definitions for throwback that I've seen before include "retort" , "Atavism" , "Reversion to an earlier type" , "someone showing old-fashioned tendencies" , "Return" .)