A touchpad is the small flat rectangle below the keys on a laptop. You slide a finger across it to move the pointer, and tap it to click. Almost every laptop has one, so it is a word you use constantly once you know it. Two things to notice. First, plenty of people call it a trackpad instead — Apple uses trackpad, and among Mac users that is simply the normal word; touchpad is the more general, more technical term, and the one Windows and manufacturers use. They mean the same object. Second, 'touchpad' is also used for other flat touch-sensitive panels: the pad on a games controller, or the panel by a door where you enter a code. Context tells you which. As a word it is transparent and modern — put together from two ordinary words, easy to guess. The plural is touchpads, and it is usually written as one word now, though you will still see 'touch pad' in older manuals.