drum machine
n (Instruments) a synthesizer specially programmed to reproduce the sound of drums and other percussion instruments in variable rhythms and combinations selected by the musician; the resulting beat is produced continually until stopped or changed
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014