ponderous, collegiate, colorless, dead, jading, monotone, drab, prostrate, savorless, two-dimensional, antisocial, drear, unmusical, monochromatic, assistant, old, matted, disembodied, clerical, croaky, unglamorous, jejune, unmelodious, mind-numbing, matte, excite, tiring, multiple, stodgy, numbing, bland, casual, leaden, unchanged, single, categorical, unconditional, dusty, savourless, flavourless, stupid, irksome, grating, fruity, flavorless, appealing, pedestrian, matt, tame, associate, drudging, wearying, ho-hum, heavy, plane, unglamourous, arid, vapid, adenoidal, unmelodic, collaborative, compressed, stuffy, stale, categoric, monotonic, ceremonial, adjunct, weary, cooperative, mat, weariful, brittle, various, varying, slow, breathy
boring (part of speech: adjective)
regular (part of speech: adjective)
everyday, mundane, habitual, periodic, cyclical, commonplace, ordinary, continual, constant, standard, familiar, epochal, chronic, predominating, steady, stock, frequent, orthodox, accustomed, general, average, recurrent, prevailing, regular, rhythmic, metronomic, routine, conventional, universal, traditional, common, customary, normal, usual, canonical
continuous (part of speech: adjective)
invariable, seamless, unchangeable, repeated, consecutive, unceasing, persistent, everlasting, coherent, flat, sequential, undeviating, unvarying, continuing, nonstop, undying, homogeneous, incessant, un-intermittent, gapless, straight, featureless, level, perennial, unending, interminable, perpetual, indefatigable, endless, connected, unremitting, unbroken, uniform, lasting, ceaseless, consistent, robot-like, continuous, even, monolithic, unchanging, repetitive
- From this ground, the view to the south as a medium point, was over as dark and monotonous a country as could well be described. - "Expedition into Central Australia", Charles Sturt.
- She walked backward and forward in that monotonous wandering for some time before she was able to steady her thoughts- before she was able to bring the scattered forces of her narrow intellect to bear upon the one all- important subject of the threat contained in the barrister's letter. - "Lady Audley's Secret", Mary Elizabeth Braddon.
- His Honor was looking over some papers, and the monotonous tones of the witness diverted attention. - "The Underdog", F. Hopkinson Smith.