Knowing in Zaporizhzhia war ended (5)
I believe the answer is:
aware
'knowing' is the definition.
(I've seen this before)
'in zaporizhzhia war ended' is the wordplay.
'in' says the answer is hidden in the clue.
'AWARE' is hidden within 'zaporizhzhia war ended'.
(Other definitions for aware that I've seen before include "Having knowledge or realisation" , "Having knowledge of, informed" , "Conscious or having knowledge of" , "Conscious, sentient" , "Cognizant" .)