| in the dumps(expression, adjective, idiom, dull, unhappy) |
| inanimate(adjective, dull, flat, low, sad) |
| indifferent(adjective, dull, flat, low, sad) |
| indolent(adjective, dull, slow, idle, weary) |
| inelaborate(adjective, dull, simple, dreary, uninteresting) |
| inert(adjective, dull, quiet, flat, slow) |
| inexcitable |
| innocuous(adjective, dull, weak, dead, tedious) |
| inoperative(adjective, dull, idle, sluggish, lazy) |
| insensible(adjective, indifferent, unconcerned, uncaring, passive) |
| jarring(adjective, dull, unhappy, dark, gloomy) |
| jobless(adjective, dull, idle, sluggish, lazy) |
| joyless(adjective, dull, unhappy, dark, gloomy) |
| lackadaisical(adjective, dull, flat, low, sad) |
| lackluster(adjective, dull, flat, low, sad) |
| laggard(adjective, dull, heavy, stupid, weary) |
| laid-back(adjective, dull, flat, slow, heavy) |
| laid back(expression, adjective, lazy, slack, uncaring) |
| languishing(adjective, dull, flat, low, sad) |
| languorous(adjective, dull, flat, low, sad) |