1.
monotonous, humdrum, tedious
Lacking in variety or change, resulting in boredom. Describes repetitive situations, routines, or sounds that feel dull due to their uniformity.
単調 describes something that lacks variety or change, making it feel dull or tedious. It is a na-adjective with a generally negative connotation.
Forms
単 (single, simple) + 調 (tone, key). Literally "single tone," evoking the idea of no variation in pitch or pattern.