internecine

equivalents

bloody

internal

synonyms

baneful

brutal

calamitous

cataclysmal

cataclysmic

catastrophic

consuming

consumptive

deadly

death-bringing

deathful

deathly

demolishing

demolitionary

depredatory

desolating

destroying

destructive

destructive

devastating

disastrous

doomful

fatal

fateful

feral

fratricidal

intramural

killing

lethal

malign

malignant

mortal

nihilist

nihilistic

pernicious

ravaging

ruining

ruinous

savage

self-destructive

subversionary

subversive

suicidal

vandalic

vandalish

vandalistic

virulent

wasteful

wasting

withering

same-contexts

age-old

arab-israeli

bicoastal

dynastic

factional

fratricidal

generational

guerilla

hand-to-hand

inter-tribal

interdepartmental

interservice

jurisdictional

life-and-death

long-running

long-standing

low-intensity

rancorous

sanguinary

sectarian

sectional

unending

wordy