| slow |
| sober |
| stuffy(adjective, dull, flat, stupid, dead) |
| tedious(adjective, dull, weak, simple, flat) |
| uneventful(adjective, dull, simple, clean, plain) |
| unexceptional(adjective, dull, simple, clean, plain) |
| unimaginative(adjective, dull, simple, flat, excite) |
| unmemorable(adjective, dull, ordinary, empty, lifeless) |
| washy |
| wishy-washy(dull, light, weak, soft, feeble) |
| abstract(adjective, cool, cold, indifferent, detached) |
| aloof |
| bleak |
| clear(neutral, uncolored, uncoloured) |
| common(adjective, dull, simple, flat, rough) |
| detached(adjective, cool, cold, indifferent, unfriendly) |
| dim(adjective, dull, light, weak, soft) |
| discolored(beat, dirty, dim, white, exhausted) |
| disinterested(adjective, cool, cold, indifferent, detached) |
| dismal(adjective, dull, soft, obscure, flat) |