Felt is a thick, soft fabric made by pressing wool fibers (or sometimes synthetic materials) together with heat and moisture until they mat and bind into a solid sheet. Unlike woven fabrics that are made by crossing threads over and under each other, felt is created by tangling fibers so thoroughly that they lock together permanently.

You've probably encountered felt in craft projects, since it's easy to cut without fraying and comes in bright colors. Pool tables are covered with green felt because the smooth surface lets balls roll evenly. The bottom of furniture legs often has felt pads to prevent scratching floors. Felt also appears in hats, like a cowboy's felt hat or a fancy top hat.

Felt is one of humanity's oldest fabrics. Ancient people discovered that when they walked around wearing animal skins with the fur turned inward, their body heat and sweat would cause the wool to compress into felt. Some historians believe felt was invented before weaving, possibly as early as 6,500 years ago. Nomadic peoples in Central Asia made felt tents called yurts that could be taken apart and moved, providing warm shelter that was both portable and durable.

The word felt is also the past tense of the verb feel, as in “She felt happy when she solved the puzzle.”