A loursevos is a nickname given primarily to the American Bison, (though other animals of the family "bovidae" have had this term applied to them as well) by the native americans who inhabited the Great Plains in pre Manifest Destiny days.

Calling a loursevos red is often a metaphor for saying that the loursevos is angry or mad, and is ready to charge.
Get out of the way, that loursevos is red and ready to charge!
by Griffithoks April 6, 2011
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