| latent(adjective, dull, idle, sluggish, lazy) |
| lax(adjective, dull, idle, sluggish, lazy) |
| lazy(adjective, dull, slow, indifferent, idle) |
| lead balloon(expression, adjective, dull, weak, dead) |
| limp(adjective, dull, flat, low, sad) |
| lingering(adjective, dull, moderate, low, stiff) |
| long-delayed(adjective, dull, moderate, low, stiff) |
| long-drawn-out(adjective, dull, moderate, low, boring) |
| low(adjective, dull, moderate, flat, sad) |
| low-key(adjective, dull, idle, sluggish, lazy) |
| low-spirited |
| lumpish(adjective, dull, slow, heavy, sluggish) |
| lusterless(adjective, dull, flat, boring, lifeless) |
| matte(adjective, dull, weak, flat, dead) |
| matter of fact(expression, adjective, idiom, simple, puny) |
| melancholic(adjective, dull, flat, low, sad) |
| melancholy(adjective, dull, flat, low, sad) |
| miserable(adjective, dull, unhappy, dark, gloomy) |
| moderate(adjective, dull, low, stiff, late) |
| modest(adjective, dull, simple, dreary, uninteresting) |