internecine
UK: ˌɪntəˈniːsaɪn | US: ˌɪntərˈniːsɪn
adj. (of conflict) destructive to both sides
adj. relating to slaughter or carnage
Derived from Latin internecinus ("deadly, destructive"), itself from inter ("between") + necare ("to kill"). Originally used to describe mutually destructive conflict, the term later emphasized internal strife (e.g., "internecine war"). The root nec appears in other English words like "pernicious" (thoroughly destructive) and "necrosis" (tissue death).
The internecine feud weakened both factions irreparably.
Historians studied the internecine violence of the civil war.
The company collapsed due to internecine leadership struggles.
Internecine conflicts often leave no true victors.
The tribe’s internecine disputes made them vulnerable to invaders.