monotony

noun

Etymology: From French monotonie, from Late Latin monotonia, from Ancient Greek μονοτονία (monotonía, “sameness of tone, monotony”).

1. Tedium as a result of repetition or a lack of variety.

   “It matters little to trace the rapidity of the land journey, or the monotony of the sea voyage—alike unmarked by adventure. Robert Evelyn landed at Southampton,...”

   “Yet second-hand romance and second-hand emotion are surely better than the dull, soul-killing monotony which life brings to most of the human race.”

2. The property of a monotonic function.
3. The quality of having an unvarying tone or pitch.