Advertisement about conflict medal, say (5)
I believe the answer is:
award
'medal say' is the definition.
(medal is a kind of award)
'advertisement about conflict' is the wordplay.
'advertisement' becomes 'ad' (short for advert).
'about' indicates putting letters inside.
'conflict' becomes 'war' (war is a kind of conflict).
'ad' enclosing 'war' is 'AWARD'.
(Other definitions for award that I've seen before include "Endow" , "Give, as an honour" , "Give officially as prize or payment" , "certificate?" , "Grant, confer" .)