plume

Concise Oxford English Dictionary © 2008 Oxford University Press:
plume/pluːm/

▶noun

• 1 a long, soft feather or arrangement of feathers used by a bird for display, or worn on a hat or helmet as decoration.

• 2 a long spreading cloud of smoke or vapour.

• 3 Geology a column of magma rising by convection in the earth's mantle.

▶verb

• 1 (often as adj. plumed) decorate with or as if with feathers.

  ■ spread out in a shape resembling a feather.

• 2 (plume oneself) chiefly archaic (of a bird) preen.

  ■ feel a great sense of self-satisfaction.

– derivatives
plumeless adjective.

– origin ME: from OFr., from L. pluma ‘down’.