1a long, soft feather or arrangement of feathers used by a bird for display or worn by a person for ornament:a hat with a jaunty ostrich plume Zoology a part of an animal’s body that resembles a feather:the antennae are divided into large feathery plumes 2a long cloud of smoke or vapour resembling a feather as it spreads from its point of origin:as he spoke, the word was accompanied by a white plume of breath a mass of material, typically a pollutant, spreading from a source:a radioactive plume
3 (also mantle plume) Geology a localized column of hotter magma rising by convection in the mantle, believed to cause volcanic activity in locations away from plate margins. 1 [no object] spread out in a shape resembling a feather:smoke plumed from the chimneys [with object] decorate with or as if with feathers: (as adjective plumed)rain began to beat down on my plumed cap
) chiefly archaic (of a bird) preen itself.
feel a great sense of self-satisfaction about something:she plumed herself on being cosmopolitan