| inactive(adjective, dull, slow, heavy, sluggish) |
| indolent(adjective, dull, slow, heavy, sluggish) |
| inert(adjective, dull, slow, heavy, sluggish) |
| inside(noun, informal, jail) |
| laid-back(adjective, dull, slow, heavy, sluggish) |
| languorous(adjective, dull, slow, heavy, sluggish) |
| late(adjective, slow) |
| leaden(adjective, dull, slow, heavy, sluggish) |
| leisurely(adjective, slow) |
| lethargic(adjective, dull, slow, heavy, sluggish) |
| lifeless(adjective, dull, slow, heavy, sluggish) |
| lingering(adjective, slow) |
| listless(adjective, dull, slow, heavy, sluggish) |
| lock-up |
| lumpish(adjective, dull, slow, heavy, sluggish) |
| measured(adjective, slow) |
| mooney(adjective, dull, slow, heavy, sluggish) |
| off(adjective, dull, slow, heavy, sluggish) |
| phlegmatic(adjective, dull, slow, heavy, sluggish) |
| plodding(adjective, slow) |