internecine
Concise Oxford English Dictionary © 2008 Oxford University Press:
internecine /ɪntəˈniːsʌɪn/
▶adjective destructive to both sides in a conflict.
■ relating to conflict within a group.
– origin C17: from L. internecinus, based on inter- ‘among’ + necare ‘to kill’.
'internecine' also found in these Oxford entries:
