monotonous
1. [ adjective ] sounded or spoken in a tone unvarying in pitch
Synonyms: monotone monotonic
Examples:

"the owl's faint monotonous hooting"

Related terms: unmelodious
2. [ adjective ] tediously repetitious or lacking in variety
Synonyms: humdrum
Examples:

"a humdrum existence all work and no play" "nothing is so monotonous as the sea"

Related terms: dull
Similar spelling:   monotonously
  mountainous
  monotony
  monotone
  monotonic
  Monodon
  mounting
  mountain
  Montondo