prosaic

つまらない の訳語→ bad bleak boring disappoint disgusting fool foolish fucking futile goddam horrible inadequate intolerable menial pedantic peewee rubbishy tedious unexciting uninteresting unreadable wearisome wretched zilch

荒涼とした の訳語→ desolate ragged

単純な の訳語→ absolute heedless humble mindless simple

平板な の訳語→ drab flat flattened linear

凡庸な の訳語→ dull mundane ordinary