1. The odorous fumes or vapor given off by the burning of any substance, especially by such things that emit an agreeable odor; such as, incense: "Who's wearing tht spicy perfume?"
2. The volatile particles, scent, or odor emitted by any sweet-smelling substance; the fragrance diffused by a liquid scent, exhaled by flowers, etc.: "Those roses perfume the whole garden."
3. A substance, natural or prepared, that emits, or is capable of emitting an agreeable odor; a fluid containing the essence of flowers or other odorous substances; scent.

Originally applied to a diffuse sweet-smelling odor when something was burned.

4. Etymology: from Latin per-, "throughly" + fumus, "smoke"; literally, "thoroughly smoked, full of smoke or vapor".