More on l'outrance from Infoplease:

• A l'outrance - A l'outrance To the uttermost. (Anglo-French for à outrance.) “A champion has ...
• English French - English French A kind of perversity seems to pervade many of the words which we have borrowed from ...
• Dictionary of Phrase and Fable: A - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "A"