Day proceeds for warship (7)
I believe the answer is:
frigate
'for warship' is the definition.
(frigate is a kind of warship)
'day proceeds' is the wordplay.
'day' becomes 'fri' (abbreviation for Friday).
'proceeds' becomes 'gate' (proceeds from people attending a sporting event).
'fri'+'gate'='FRIGATE'
(Other definitions for frigate that I've seen before include "Ship" , "US warship" , "Warship; -- bird" , "Type of warship" , "Naval escort vessel" .)