any musical instrument consisting of a graduated series of metal bars that may either be struck by hammers operated manually or played with a keyboard.
Origin of metallophone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
any of various musical instruments consisting of tuned metal bars struck with a hammer, such as the glockenspiel
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012