A euphemism for a most stubbornly lingering odor produced via flatulence. One's, "own brand
," similar to an, "Eau de Toilette," but rather, "Eww! De Toilette." A permutation of, "perfume." Often produced in crowded social areas where the opportunity to covertly relieve one's self is not available thus causing the rearfumist to intermittently 'puff' and 'wear' their own rearfume.
Phe-eew! I HAVE to get away from this guy's rearfume.
If she likes your rearfume, she's a keeper.