Painting forces in conflict (6)
I believe the answer is:
fresco
'painting' is the definition.
(I know that fresco is a type of painting)
'forces in conflict' is the wordplay.
'in conflict' indicates an anagram (letters clashing or in conflict with each other).
'forces' with letters rearranged gives 'FRESCO'.
(Other definitions for fresco that I've seen before include "Artwork" , "Mural painting" , "Artistic work" , "Painting using watercolours on plaster" , "Picture painted on wall or ceiling before plaster is dry" .)