plume

A plume can be a long, soft feather, especially one used for decoration on a hat, helmet, or costume. The word is also very often used for something that rises and spreads in the air or water, like a plume of smoke, steam, dust, or ash. You might see a gray plume above a fire or a white plume of steam from a train. It can also be used as a verb in an older or literary way: someone may plume themselves on an achievement, meaning they feel very proud of it.

A plume is a rich word with a few closely linked meanings. Most literally, it means a long, soft feather, especially one used for decoration. This sense brings to mind feathers on helmets, hats, costumes, or ceremonial dress. In writing, it often suggests beauty, elegance, or display, as when a bird lifts its bright plumes.

Just as commonly, plume describes a tall, spreading mass of something moving through air or water, especially smoke, steam, dust, ash, or gas. A plume of volcanic ash, a plume of black smoke, or even an underwater plume all fit this pattern. The image is of something rising, trailing, and opening out, a little like a feather.

There is also a less common verb use. To plume oneself means to feel proud or pleased with oneself, often in a showy way. This idea comes from the image of a bird arranging its feathers. So the word can move from something physical and visible, like a feather or a cloud of smoke, to a more human feeling of display, pride, or self-importance.