Old-fashioned and more suitable tailor (9)
I believe the answer is:
outfitter
'tailor' is the definition.
(I've seen this before)
'old-fashioned and more suitable' is the wordplay.
'old-fashioned' becomes 'out' (as opposed to 'in').
'and' says to put letters next to each other.
'more suitable' becomes 'fitter' ('fit' can be similar in meaning to 'suitable').
'out'+'fitter'='OUTFITTER'
(Other definitions for outfitter that I've seen before include "Trader" , "It suits one" , "Seller of clothes" , "Men's clothes shop" , "who could help in gear selection?" .)