| debilitated(adjective, lethargic) |
| enervated(adjective, lethargic) |
| idle(adjective, lethargic) |
| lifeless(adjective, dull, slow, heavy, sluggish) |
| obtuse(adjective, ability, imbecility folly) |
| phlegmatic(adjective, dull, slow, heavy, stupid) |
| slack(adjective, dull, slow, heavy, sluggish) |
| slothful(adjective, dull, slow, heavy, stupid) |
| slumberous(adjective, dull, slow, cold, heavy) |
| thick-witted(adjective, ability, stupid) |
| thickheaded(adjective, ability) |
| dead |
| doltish(adjective, ability, imbecility folly) |
| indolent(adjective, dull, slow, heavy, apathetic) |
| laid-back(adjective, dull, slow, informal, heavy) |
| leaden(adjective, dull, slow, heavy, apathetic) |
| lumpish(adjective, dull, slow, heavy, sluggish) |
| sleepy |
| somnolent |
| stagnant(adjective, dull, slow, heavy, apathetic) |