Hit, glad he receives treatment for shiner (9)
I believe the answer is:
headlight
'shiner' is the definition.
(I know that headlight is a type of shiner)
'hit glad he receives treatment' is the wordplay.
'receives treatment' indicates anagramming the letters (letters treated or processed).
'hit'+'glad'+'he'='hitgladhe'
'hitgladhe' anagrammed gives 'HEADLIGHT'.
'for' acts as a link.
(Other definitions for headlight that I've seen before include "What motorist may use" , "Car beam" , "Bright lamp on front of car etc" , "Powerful car lamp" , "Given shiner" .)