outrance
The furthest degree or extremity, going beyond bounds or propriety.
obsolete, uncountable
1819: But if the shield was touched with the sharp end of the lance, the combat was understood to be at “outrance”, that is, the knights were to fight with sharp weapons, as in actual battle. — Walter Scott, Ivanhoe
Where it comes from
From Old French oltrance (modern outrance (“excess”)), from outrer (“pass beyond”), from oltre, outre, utre, from Late Latin ultra-. Compare outrage.
Adapted from the Wiktionary entry outrance (CC BY-SA 4.0).