| faulty(adjective, bad, wrong, fake, poor) |
| weak(adjective, strong, light, slight, poor) |
| invalid(adjective, bad, weak, correct, wrong) |
| unstable(adjective, characteristic, quality, finance, banking) |
| infirm(adjective, strong, light, weak, slight) |
| unhealthy(adjective, weak, severe, disease, poor) |
| defective(adjective, bad, wrong, thin, false) |
| false(adjective, bad, light, weak, correct) |
| unreliable(adjective, dangerous, characteristic, quality, finance) |
| fallacious(adjective, bad, correct, wrong, fake) |
| wrong(adjective, bad, correct, fake, false) |
| frail(adjective, strong, light, weak, slight) |
| illogical(adjective, correct, wrong, false, silly) |
| shaky(adjective, weak, slight, thin, delicate) |
| risky(adjective, dangerous, characteristic, quality, finance) |
| erroneous(adjective, bad, correct, wrong, fake) |
| feeble(adjective, strong, light, weak, slight) |
| flawed(adjective, wrong, false, well, incorrect) |
| fragile(adjective, strong, light, weak, slight) |
| ill(adjective, weak, delicate, sick, feeble) |