скучный

1) General subject: arid, barren, barren of interest, boresome, boring, cut and dried, cut-and-dried, dead-alive, drab, dreary, dry, dryasdust, dull, dull as ditch-water, eventless, exsuccous, flat, gay (Активный вокабуляр Картмана), hack, hacker, hackney, heartbreaking, heavy, heavy footed, heavy-footed, ho hum, humdrum, humourless, inanimate, insipid, irksome, jejune, languid, lifeless, long, long winded, long-winded, longspun, matter of fact, matter-of-fact, mirthless, monotone, pedestrian, ponderous, prolix, prosaic, prosaical, prosaist, prose, prosy, quiet, repetitious, repetitive, sad, slow, slow footed, slow-footed, soggy, stodgy (о человеке), stuffy, stupid, switched off, switched-off, tame, tedious, tiresome, trying, unappetizing, undramatic, uninspiring, uninteresting, unlively, unreadable, vapid, weariful, wearing, wearisome, wearying, wisht, yawnful, monotonous, unimaginative, one-dimensional

2) Colloquial: dreadful, heart-breaking, ho-hum, moldy, mortal, mouldy, vegetable

3) American: draggy

4) Rare: witless

5) Australian slang: browned off, dead as a dodo

6) Psychology: weary

7) Abbreviation: ZZZ

8) Jargon: beige (The party is beige. Let's cruise .- Вечеринка скучная. Давай прогуляемся.), blah, no three-alarm fire, nothing, nowhere, the least, vanilla, wiped out, uncool, whitebread, nerd, punk, L7, dead, square, tired

9) Makarov: unanimated

10) Taboo: chicken-shit, dead ass, dead assed, drag-ass, drag-assed, dumb-ass

11) Phraseological unit: blow chunks