'Monotone' definitions:

Definition of 'monotone'

(from WordNet)
adjective
Of a sequence or function; consistently increasing and never decreasing or consistently decreasing and never increasing in value [syn: monotonic, monotone] [ant: nonmonotonic]
adjective
Sounded or spoken in a tone unvarying in pitch; "the owl's faint monotonous hooting" [syn: flat, monotone, monotonic, monotonous]
noun
An unchanging intonation [syn: monotone, drone, droning]
noun
A single tone repeated with different words or different rhythms (especially in rendering liturgical texts)

Definition of 'Monotone'

From: GCIDE
  • Monotone \Mon"o*tone\, n. [See Monotonous, Monotony.]
  • 1. (Mus.) A single unvaried tone or sound. [1913 Webster]
  • 2. (Rhet.) The utterance of successive syllables, words, or sentences, on one unvaried key or line of pitch. [1913 Webster] Monotonic