n. The act of copulating, as bucks and does.n. A vice peculiar to the horses of Mexico, Texas, and the western American plains, of Spanish descent, and to mules. See buck, verbGiven to bucking; addicted to the practice of bucking: as, a bucking horse.n. The act or process of steeping or soaking in lye or caustic soda, as in bleaching cotton thread, etc.n. The act of breaking or pulverizing ore.