| dull(adjective, hard, weak, simple, flat) |
| dreary(adjective, dull, blue, sad, unhappy) |
| gloomy(adjective, dull, blue, sad, unhappy) |
| boring(adjective, dull, weak, simple, flat) |
| soul-crushing |
| dark(adjective, calm, dull, quiet, soft) |
| dingy(adjective, dull, soft, obscure, lead) |
| gray(adjective, dull, dark, gloomy, dirty) |
| slut(noun, uncleanness, libertine) |
| grey(adjective, dull, lead, leaden, mousy) |
| somber(adjective, calm, dull, quiet, soft) |
| colourless(adjective, dull) |
| cheerless(adjective, dull, blue, sad, unhappy) |
| dismal(adjective, dull, soft, obscure, flat) |
| flat(adjective, dull, hard, simple, soft) |
| murky(adjective, dull, soft, obscure, flat) |
| monotonous(adjective, dull, weak, simple, plain) |
| sombre(adjective, dull, flat, boring, lifeless) |
| prosaic(adjective, dull, weak, simple, flat) |
| tedious(adjective, dull, weak, simple, plain) |