| lurid(adjective, dull, light, soft, poor) |
| monotonous(adjective, dull, weak, dark, heavy) |
| night(noun, part, dark, darkness, vesper) |
| sad(adjective, blue, depression, woe) |
| sooty(adjective, dull, soft, obscure, flat) |
| subfusc(adjective, soft, obscure, flat, dark) |
| tone down(verb, expression, phrasal verb, dull, quiet) |
| twilight(noun, adjective, dull, close, quiet) |
| unilluminated(adjective, dull, obscure, dark, gloomy) |
| unintelligent(adjective, dull, simple, slow, foolish) |
| veil(verb, cover, obscure, confuse, hide) |
| wan(verb, adjective, dull, quiet, light) |
| Stygian(adjective, dull, obscure, dark, gloomy) |
| adumbrate(verb, cover, obscure, confuse, hide) |
| ashen(adjective, dull, quiet, light, soft) |
| blah(adjective, dull, weak, flat, dark) |
| blanch(verb, reduce, diminish) |
| blot out(verb, expression, obscure, conceal, eclipse) |
| boring(adjective, dull, weak, simple, flat) |
| bovine(adjective, dull) |