A large hoofed mammal (Equus caballus) having a short-haired coat, a long mane, and a long tail, domesticated since ancient times and used for riding and for drawing or carrying loads. An adult male horse; a stallion. Any of various equine mammals, such as the wild Asian species E. przewalskii or certain extinct forms related ancestrally to the modern horse. A frame or device, usually with four legs, used for supporting or holding. Sports A vaulting horse. Slang for "Heroin". Horsepower. Often used in the plural. Mounted soldiers; cavalry: a squadron of horse. Geology A block of rock interrupting a vein and containing no minerals. Geology A large block of displaced rock that is caught along a fault. To provide with a horse. To haul or hoist energetically: "Things had changed little since the days of the pyramids, with building materials being horsed into place by muscle power\u201d ( Henry Allen). To be in heat. Used of a mare. Of or relating to a horse: a horse blanket. Mounted on horses: horse guards. Drawn or operated by a horse. Larger or cruder than others that are similar: horse pills. horse around Informal To indulge in horseplay or frivolous activity: Stop horsing around and get to work. another Another matter entirely; something else. beat To continue to pursue a cause that has no hope of success. beat To dwell tiresomely on a matter that has already been decided. be To be or become disdainful, superior, or conceited. hold (one's) horses To restrain oneself. the horse's mouth A source of information regarded as original or unimpeachable.