internecine

adjective

in·​ter·​ne·​cine ˌin-tər-ˈne-ˌsēn 

-ˈnē-sᵊn,

-ˈnē-ˌsīn,

-nə-ˈsēn;

in-ˈtər-nə-ˌsēn

1

: of, relating to, or involving conflict within a group

bitter internecine feuds

2

: marked by slaughter : deadly

especially : mutually destructive

Did you know?

Internecine comes from the Latin internecinus ("fought to the death" or "destructive"), which traces to the verb "necare" ("to kill") and the prefix inter-. ("Inter-" usually means "between" or "mutual" in Latin, but it can also indicate the completion of an action.) Internecine meant "deadly" when it appeared in English in the early 17th century, but when Samuel Johnson entered it in his dictionary almost a century later, he was apparently misled by "inter-" and defined the word as "endeavouring mutual destruction." Johnson's definition was carried into later dictionaries, and before long his sense was the dominant meaning of the word. "Internecine" developed the association with internal group conflict in the 20th century, and that's the most common sense today.

Examples of internecine in a Sentence

a political party that has suffered because of bitter internecine rivalries

Recent Examples on the Web

And third, the videos play a role in internecine warfare among jihadist groups in places such as Syria and Iraq, where rival organizations jockey for power and influence. —Andrew Byers, Foreign Affairs, 5 May 2017

Everyday voters outside the conservative ecosystem are much less interested in internecine ideological conflicts. —Philip Wegmann, Orlando Sentinel, 1 Feb. 2025

But in either case, the United States will finally be drawn feet first into the internecine struggle that is reshaping the institutions of the Middle East. —Andrew L. Peek, Foreign Affairs, 11 Nov. 2016

But as the group reached their peak, Sly fell prey to personal hardship: various external pressures and internecine conflicts within the group exacerbated a crippling drug addiction that ensured the band’s slow dissolution. —Vikram Murthi, IndieWire, 24 Jan. 2025

Word History

Etymology

Latin internecinus, from internecare to destroy, kill, from inter- + necare to kill, from nec-, nex violent death — more at noxious

First Known Use

1642, in the meaning defined at sense 2

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Kids Definition

internecine

adjective

in·​ter·​ne·​cine ˈint-ər-ˈnes-ˌēn 

-ˈnē-ˌsīn;

in-ˈtər-nə-ˌsēn

1

: marked by slaughter : deadly

2

: of, relating to, or involving conflict within a group

internecine feuds