Ocean, river or burn? (4)
I believe the answer is:
sear
'burn?' is the definition.
(sear can mean to burn)
'ocean river' is the wordplay.
'ocean' becomes 'sea' (synonyms).
'river' becomes 'r' (abbreviation for river).
'sea'+'r'='SEAR'
'or' acts as a link.
(Other definitions for sear that I've seen before include "Burn briefly" , "Make very hot and dry" , "Dried-up, parched" , "Cook (quickly at great heat)" , "Dried up, parched" .)