definition of
monotony

[1] #1 monotony n. [humdrum, sameness] the quality of wearisome constancy, routine, and lack of variety; "he had never grown accustomed to the monotony of his work"; "he was sick of the humdrum of his fellow prisoners"; "he hated the sameness of the food the college served". wn

[2] #2 monotony n. constancy of tone or pitch or inflection. wn