Old way the French primarily regarded a stableman (6)
I believe the answer is:
ostler
'a stableman' is the definition.
(synonyms)
'old way the french primarily regarded' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'way' becomes 'st' (abbreviation for street).
'the french' becomes 'le' ('the' in French).
'primarily' indicates taking the first letters.
The initial letter of 'regarded' is 'r'.
'o'+'st'+'le'+'r'='OSTLER'
(Other definitions for ostler that I've seen before include "Groom at inn" , "Horseman at the inn of old" , "Old stableman at an inn -- sterol (anag)" , "One taking care of horses at an inn" , "Horse man" .)