Being, or having the salient properties of, a monotone function.
Having a single unvaried pitch.
A piece of writing in one strain throughout.
A single unvaried tone of speech or a sound.
To speak in a monotone.
To exercise on a treadmill.
To keep busy, for example with work or with other tasks, without being able to get ahead or make progress towards long-term goals.
A mill worked by horses, dogs, etc., treading an endless belt.
A piece of indoor sporting equipment used to allow for the motions of running or walking while staying in one place.
A mill worked by persons treading upon steps on the periphery of a wide wheel having a horizontal axis. It was used principally as a means of prison discipline.
A process or situation in which continued effort leads to or is required for remaining at a particular state or level without moving ahead.