Definition: A device that controls the flow of a gas or fluid through a pipe.

Alright class, settle down and let’s take a look! Today we’re tackling a word, quite neat and true, “Valves” – it’s something you should know for you. The dictionary tells us, clear and bright, "A device that controls the flow with all its might!" Think of it like this, if you please: Imagine water flowing with such ease! But sometimes we need to stop the stream, Or change the speed, a fluid dream. That’s where valves come in, you see, Like little gatekeepers, for you and me! They open wide, or shut quite tight, To manage flow with perfect light. Whether it's gas, or liquid too, Valves direct the movement, just for you! So "valves" control a flow, it’s plain to see, A crucial part of machinery! Does that make sense? Any questions, my dears?