Dictionary.com
Thesaurus.com

nonharmonic tone

American  
[non-hahr-mon-ik, non-] / ˈnɒn hɑrˈmɒn ɪk, ˌnɒn- /

noun

Music.
  1. a tone sounding with a chord of which it is not a chord tone.


Etymology

Origin of nonharmonic tone

non- + harmonic