Sooty means covered with or colored like soot, the black powdery substance that comes from burning wood, coal, or other materials. If you've ever seen the dark smudges inside a fireplace or the black marks left by candle smoke on a ceiling, you've seen soot.

When something is described as sooty, it might be literally covered in this black residue. A chimney sweep's face might become sooty after a day of cleaning fireplaces. The glass door of a wood stove often gets sooty on the inside from smoke. In old industrial cities, buildings sometimes turned sooty from decades of coal smoke in the air.

The word can also describe something that's simply the deep, dark color of soot, even if it's not actually dirty. A writer might describe storm clouds as having a sooty darkness or a bird's feathers as sooty black. The word carries a sense of darkness that's not quite pure black but rather dingy, smudged, or smoky.

Interestingly, several bird species are called “sooty” because of their dark coloring. The sooty tern and sooty shearwater, for example, both have dark gray or blackish feathers that reminded early naturalists of soot's distinctive color.