adjective

lacking excitement or variety; boringly monotonous.

humdrum routine work

mundane,dull,dreary,boring,tedious,monotonous,banal,ho-hum,tiresome,wearisome,prosaic,unexciting,uninteresting,uneventful,unvarying,unvaried,unremarkable,repetitive,repetitious,routine,ordinary,everyday,day-to-day,quotidian,run-of-the-mill,commonplace,common,workaday,usual,pedestrian,customary,regular,normal,garden variety,typical,vanilla,plain vanilla,common or garden,banausic

noun

monotonous routine.

an escape from the humdrum of his life