monotone

UK: /ˈmɒnətəʊn/ US: /ˈmɑnəˌtoʊn/ ,(mon′ə tōn′)

WordReference Random House Learner's Dictionary of American English © 2025

mon•o•tone /ˈmɑnəˌtoʊn/   n. [countable* usually singular]

1. a sound of one unchanging tone or pitch:
   speaking in a boring monotone.

See -ton-.

WordReference Random House Unabridged Dictionary of American English © 2025

mon•o•tone  (mon′ə tōn′), n. 

1. a vocal utterance or series of speech sounds in one unvaried tone.
2. a single tone without harmony or variation in pitch.
3. recitation or singing of words in such a tone.
4. a person who is unable to discriminate between or to reproduce differences in musical pitch, esp. in singing.
5. sameness of tone or color, sometimes to a boring degree.

adj. 

6. monotonous.
7. consisting of or characterized by a uniform tone of one color:
   a monotone drape.
   Cf. monochromatic (defs. 1, 2).
8. [Math.] monotonic (def. 2).

• Late Greek monótonos monotonous
• French monotone
• 1635–45

Collins Concise English Dictionary © HarperCollins Publishers::

monotone / ˈmɒnəˌtəʊn/ noun

1. a single unvaried pitch level in speech, sound, etc
2. utterance, etc, without change of pitch
3. lack of variety in style, expression. etc

adjective

1. unvarying or monotonous