| heavy(adjective, dull, quiet, weak, easy) |
| lackadaisical(adjective, dull, weak, easy, careless) |
| languorous(adjective, dull, weak, easy, careless) |
| slow down(verb, phrasal verb, expression, passivity, retardation) |
| tame(verb, adjective, calm, control, cool) |
| uninteresting(adjective, dull, boring, tedious, dreary) |
| retarded(adjective, dull, time, ability, offensive) |
| arrest(verb, stop, reduce, restrain, halt) |
| decelerate(verb, reduce, delay, hinder, slow) |
| dim-witted(adjective, dull, simple, foolish, stupid) |
| hold back(verb, expression, phrasal verb, stop, control) |
| laggard(adjective, adverb, dull, easy, careless) |
| remiss(adjective, dull, careless, indifferent, deliberate) |
| set back(verb, phrasal verb, time, help, cause) |
| simple(adjective, dull, light, easy, ability) |
| soporific(adjective, dull, weariness) |
| tiresome(adjective, dull, boring, tedious, dreary) |
| unintelligent(adjective, dull, simple, mind, think) |
| abate(verb, stop, calm, control, dull) |
| block(verb, control, delay, moderate, extend) |