Foliage is the leaves of a tree or plant, especially when you're talking about many leaves together. When autumn arrives and the foliage turns brilliant shades of red, orange, and yellow, people drive through the countryside just to see it. When a jungle explorer hacks through dense foliage, they're cutting their way through thick layers of leaves and branches.

The word usually refers to leaves in their natural, growing state rather than individual fallen leaves. A gardener might plant shrubs with colorful foliage to make a yard more interesting, or choose plants with thick foliage to create privacy. Photographers wait for “peak foliage” in fall, when the leaves look their most spectacular.

In literature, authors often describe foliage to set a scene: dark foliage creates a mysterious forest, while lush green foliage suggests a thriving, healthy landscape. Foliage is the leafy covering that makes forests dense and gives trees their shape and color through the seasons.