Dressing and fashion an aim, yes? No (10)
I believe the answer is:
mayonnaise
'dressing' is the definition.
(mayonnaise is a kind of dressing)
'fashion an aim yes? no' is the wordplay.
'fashion' is an anagram indicator.
'an'+'aim'+'yes'+'no'='anaimyesno'
'anaimyesno' with letters rearranged gives 'MAYONNAISE'.
'and' is the link.
(Other definitions for mayonnaise that I've seen before include "Salad dressing" , "Creamy dressing" , "which is saucy" , "7 for salad" , "Egg/oil sauce" .)