D defs.my
Entry 2 senses Webster, 1913

Monotony

/mən-ät'-ən-ē/ · Mo·not·o·ny · IPA /məˈnɑtəni/
01 n. A frequent recurrence of the same tone or sound, producing a dull uniformity; absence of variety, as in speaking or singing.
  1. 1.
    A frequent recurrence of the same tone or sound, producing a dull uniformity; absence of variety, as in speaking or singing.
  2. 2.
    Any irksome sameness, or want of variety.
    “At sea, everything that breaks the monotony of the surrounding expanse attracts attention.” W. Irving.