IPA: /ˌɪntəˈniːsaɪn/
KK: /ˌɪntərˈnisiːn/
Relating to conflict or struggle that causes destruction or harm to both sides involved.
The internecine conflict left the community divided and weakened.
Internecine is formed from "inter-" (meaning between) and "necare" (meaning to kill). The word describes conflict or struggle that results in mutual destruction, particularly within a group or organization.
Think of a situation where conflict happens 'between' ('inter-') members of the same group, leading to 'killing' ('necare') each other — that's why internecine refers to destructive internal conflict.
No commonly confused words.