The word "cap" can refer to several things depending on the context. Most commonly, it is a noun that denotes a soft, flat hat that fits closely to the head. It can also be used as a verb meaning to limit or restrict something, such as capping expenses. In some contexts, "cap" can refer to a protective covering, like a bottle cap.
The word "cap" originates from the Middle English word "cappe," which is derived from the Old French word "cape," meaning "cape" or "cloak." The Latin root "cappa" means "cloak" as well, emphasizing its association with headwear or coverings.