Wagoner, abandoning state of conflict, departed (4)
I believe the answer is:
gone
'departed' is the definition.
(synonyms)
'wagoner abandoning state of conflict' is the wordplay.
'abandoning' indicates named letters should be taken away.
'state of conflict' becomes 'war' (I've seen this before).
'wagoner' with 'war' taken away is 'GONE'.
(Other definitions for gone that I've seen before include "Moved - died" , "Departed or dead" , "Well in the past" , "Departed or no longer available" , "Departed, left" .)