A setter’s offspring, might one say? (3)
I believe the answer is:
sun
'a setter's' is the definition.
(the sun sets every day)
'offspring might one say?' is the wordplay.
'offspring' becomes 'son' (male offspring).
'might one say?' shows a homophone (sound like).
'son' is a homophone of 'SUN'.
(Other definitions for sun that I've seen before include "Star that provides light and heat for a solar system" , "Hub of our planetary system" , "Nice weather" , "Dawn riser" , "Louis XIV of France was known as The . . . King" .)