1399, "a feather" (especially a large and conspicuous one), from O.Fr. plume, from L. pluma "feather, down," from PIE base *pleus- "to pluck, a feather, fleece" (cf. O.E. fleos "fleece"). Meaning "a long streamer of smoke, etc." is first attested 1878. The verb meaning "to dress the feathers" is from 1702.
A body of magma that rises from the Earth's mantle into the crust. ◇ If a plume rises to the Earth's surface, it erupts as lava. ◇ If it remains below the Earth's surface, it eventually solidifies into a body of rock known as a pluton.
An area in air, water, soil, or rock containing pollutants released from a single source. A plume often spreads in the environment due to the action of wind, currents, or gravity.