Definition of valve

The word "valve" originally comes from the Latin word "valva," which means "flap" or "door." This Latin word itself can be traced back to the Proto-Indo-European root "kwel-, kvelh-, keul-, kuol-," which means "to shut, stop, or cover." In the 17th century, the term "valve" was first used in connection with anatomical structures in the human body, such as the heart and lungs. These structures were compared to doors that controlled the flow of fluids or gases. In the late 19th century, the word "valve" began to be used more generally to refer to mechanical devices that regulate the flow of liquids or gases, such as the check valves and throttle valves used in plumbing and engineering. Today, the term "valve" is widely used in various scientific, technical, and industrial fields, including chemistry, physics, electronics, and biology, to describe a wide range of devices and mechanisms that perform similar functions to the ones originally associated with the flaps and doors in the human body.