- 1a cloud of something that rises and curves upward in the air a plume of smoke A radioactive plume could reach the city within hours.
- 2a large feather a black hat with an ostrich plume
- 3a group of feathers or long thin pieces of material tied together and often used as a decoration The red plume on the horse's head was nodding to the rhythm of its steps. see nom de plume
Check pronunciation: plume