County clinic provides dressing (4)
I believe the answer is:
mayo
'county' is the definition.
(county of Ireland)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for mayo that I've seen before include "Ir. county; salad dressing" , "Thick creamy dressing" , "Cold, creamy sauce (abbr)" , "Eg, Braeburn or Cox" , "Salad dressing (abbr)" .)