wearisome uniformity or lack of variety, as in occupation or scenery.

the continuance of an unvarying sound; monotone.

sameness of tone or pitch, as in speaking.

noun

change , color , excitement , liveliness , variability , versatility

noun

colorlessness , continuance , continuity , dreariness , dryness , dullness , ennui , equability , evenness , flatness , humdrum * , identicalness , invariability , levelness , likeness , monotone , monotonousness , oneness , repetitiousness , repetitiveness , routine , same old thing , similarity , tediousness , tedium , tiresomeness , unchangeableness , uniformity , wearisomeness , humdrum , sameness , boredom , redundancy