monotonicity
nounUK /ˌmɒnəˈtɒnɪsəti/
US /ˌmɑːnəˈtoʊnɪsəti/
Monotonicity means something only goes one way, like always up or always down, and never turns back.
The monotonicity of the graph made it easy to see that the price kept rising every year.
OTHER MEANINGS
2. In math, a function's quality of always increasing or always decreasing.
The teacher explained the monotonicity of the function before drawing its curve.
3. The quality of a sound staying on the same pitch without rising or falling.
The monotonicity of his voice made the long speech hard to follow.
4. The state of something staying the same and never changing.
The monotonicity of the schedule meant every day looked exactly the same.