of or relating to an oscillating system that is not undergoing simple harmonic motion.
Origin of anharmonic
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
physics of or concerned with an oscillation whose frequency is not an integral factor or multiple of the base frequency
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