Adjectival form of bloodmouth, pejoratively used by militant vegans to describe people who eat meat. Sometimes used as by omnivores and carnivores as a badge of honor, particularly among those who like their steaks very rare.
Fred is a real bloodmouthed carnist; he eats steak so rare that a goodvet could still save it.
Becky: OMG isn't Paul soooo hot!
Rachel: Yeah, but I heard he's a bloodmouth!
Becky: You mean like he eats meat?
Rachel: No, he's totally vegan, but I heard he ate Sarah out on her period and loved it.
Becky: Oooh kinky. I like kinky. ;)