D defs.my
Entry 2 senses Webster, 1913

Monotone

/män'-ət-ōnˌ/ · Mon·o·tone · IPA /ˈmɑ.nə.toʊn/
01 n. A single unvaried tone or sound.
  1. 1.
    A single unvaried tone or sound.(Mus.)
  2. 2.
    The utterance of successive syllables, words, or sentences, on one unvaried key or line of pitch.(Rhet.)