Crusade (8)
'crusade' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for holy war that I've seen before include "Jihad" , "Religious conflict" .)
'crusade' is the definition.
(I know that crusade is a more specific form of campaign)
This is all the clue.
(Other definitions for campaign that I've seen before include "electioneering" , "Electioneer" , "A series of planned activities, as for advertising" , "Organised course of action" , "Plan of action" .)