Before noon, Heath produces his main ally (7)
I believe the answer is:
america
'his main ally' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'before noon heath' is the wordplay.
'before noon' becomes 'am'.
'heath' becomes 'erica' (erica is a kind of heath).
'am'+'erica'='AMERICA'
'produces' is the link.
Can you help me to learn more?
(Other definitions for america that I've seen before include "Continent named after Vespucci" , "'Country named after Vespucci, Italian navigator (7)'" , "huge landmass" , "Race aim (anag)" , "Country bordering Mexico" .)