| gradual(adjective, calm, quiet, smooth, soft) |
| apathetic(adjective, characteristic, dull, quiet, weak) |
| half-assed |
| idle(adjective, dull, fail, diminish, decrease) |
| phlegmatic(adjective, characteristic, dull, weak, easy) |
| behindhand(adjective, adverb, time, property, sluggish) |
| sleepy(adjective, state, dull, quiet, careless) |
| dim(adjective, dull, quiet, simple, diminish) |
| obtuse(adjective, dull, simple, heavy, silly) |
| thick(adjective, dull, simple, silly, foolish) |
| indolent(adjective, dull, simple, careless, relaxed) |
| inert(adjective, state, dull, quiet, weak) |
| languid(adjective, calm, dull, quiet, light) |
| dilatory(adjective, adverb, dull, easy, careless) |
| dumb(adjective, dull, simple, heavy, silly) |
| half ass |
| leaden(adjective, characteristic, dull, weak, easy) |
| soul-crushing |
| late(adjective, adverb, dull, time, property) |
| boring(adjective, dull, quiet, simple, flat) |