n. 25B6; noun
the monotony of everyday life : TEDIUM, tediousness, lack of variety, dullness, boredom, repetitiveness, repetitiousness, uniformity, routineness, wearisomeness, tiresomeness; lack of excitement, uneventfulness, dreariness, colourlessness, featurelessness; informal deadliness.
the monotony of her voice : TONELESSNESS, flatness.