boring, deadening, dull, ho-hum, irksome, slow, tedious, tiresome, wearisome(adj)

so lacking in interest as to cause mental weariness

"a boring evening with uninteresting people"; "the deadening effect of some routine tasks"; "a dull play"; "his competent but dull performance"; "a ho-hum speaker who couldn't capture their attention"; "what an irksome task the writing of long letters is"- Edmund Burke; "tedious days on the train"; "the tiresome chirping of a cricket"- Mark Twain; "other people's dreams are dreadfully wearisome"

ho-hum(Adjective)

Boring; not interesting or novel.

She wore ho-hum clothes, but practical ones.

ho-hum(Interjection)

Used to express boredom, disinterest or lack of novelty.

Look at all this paperwork. Ho-hum!