holy war

WordReference Random House Unabridged Dictionary of American English © 2025

ho′ly war′, 

1. a war waged for what is supposed or proclaimed to be a holy purpose, as the defense of faith.
2. any disagreement or argument between fanatical proponents of radically differing beliefs, opinions, etc.:
   a holy war on the merits of rival computer operating systems; a holy war about welfare reform.

• 1685–95

holy war, +

1. any disagreement or argument between fanatical proponents of radically differing beliefs, opinions, etc.:
   a holy war on the merits of computer operating systems; a holy war about welfare reform.