(a.) Commonplace; trivial; hackneyed; trite\.

asinine average back-number bewhiskered bland bromidic central cliched common commonplace corny cut-and-dried everyday fade familiar fatuous flat fusty hackney hackneyed hoary humdrum intermediary intermediate jejune mean medial median mediocre medium middle-of-the-road middling milk-and-water moderate moth-eaten musty namby-pamby normal old old hat ordinary pedestrian petty platitudinous routine sapless set silly simple square stale standard stereotyped stock threadbare timeworn tired trite trivial truistic unimaginative unoriginal usual vapid warmed-over waterish watery well-known well-worn wishy-washy worn worn thin