Burnt by water, is inflamed (6)
I believe the answer is:
seared
'burnt' is the definition.
(thesaurus)
'by water is inflamed' is the wordplay.
'by' says to put letters next to each other.
'water' becomes 'sea' (sea is a kind of water**).
'is inflamed' becomes 'red' ('red' can be a synonym of 'inflamed').
'sea'+'red' is 'SEARED'.
(Other definitions for seared that I've seen before include "burned" , "dried up" , "Scorched, singed" , "Scorched on the surface (6).[BO]" .)