Old hat in good shape for suit, say (6)
I believe the answer is:
outfit
'suit say' is the definition.
'outfit' can be an answer for 'suit' (thesaurus). I am not sure about the 'say' bit.
'old hat in good shape' is the wordplay.
'old hat' becomes 'out' (I've seen this before).
'in good shape' becomes 'fit' (I can't justify this - if you can you should give a lot more credence to this answer).
'out'+'fit'='OUTFIT'
'for' is the link.
Can you help me to learn more?
(Other definitions for outfit that I've seen before include "Cohesive unit, eg a military company" , "Business" , "Organisation or set of clothing" , "suit" , "what to wear?" .)