Drinks ruined seat (4)
I believe the answer is:
teas
'drinks' is the definition.
(tea is a kind of drink)
'ruined seat' is the wordplay.
'ruined' indicates anagramming the letters.
'seat' is an anagram of 'TEAS'.
(Other definitions for teas that I've seen before include "Afternoon meals" , "Beverages from leaves" , "Hot drinks" , "Beverage made by steeping leaves in water" .)