Males ruining dinners, say (5)
I believe the answer is:
meals
'dinners say' is the definition.
(dinner is a kind of meal)
'males ruining' is the wordplay.
'ruining' indicates an anagram.
'males' with letters rearranged gives 'MEALS'.
(Other definitions for meals that I've seen before include "Repasts" , "Breakfast, dinner and tea" , "Collations" .)