| unimaginable(adjective, belief, unreasonable, useless, size) |
| unthinkable(adjective, unusual, belief, exceptional, unreasonable) |
| impossible(adjective, extraordinary, belief, unreasonable, dubious) |
| incredible(adjective, great, flat, poor, thin) |
| unbelievable(adjective, great, obscure, flat, poor) |
| implausible(adjective, great, flat, poor, thin) |
| improbable(adjective, great, flat, poor, thin) |
| fantastic(adjective, unusual, belief, strange, superb) |
| absurd(adjective, unreasonable, useless, doubtful, dubious) |
| preposterous(adjective, obscure, unreasonable, useless, absurd) |
| incomprehensible(adjective, belief, understandable) |
| unlikely(adjective, light, obscure, thin, belief) |
| rare(adjective, obscure, extraordinary, unusual, belief) |
| doubtful(adjective, extraordinary, unreasonable, amazing, dubious) |
| extraordinary(adjective, great, unusual, belief, strange) |
| staggering(adjective, extraordinary, belief, amazing, astonishing) |
| strange(adjective, light, thin, unusual, belief) |
| thin(adjective, light, weak, great, poor) |
| unconvincing(adjective, great, flat, poor, thin) |
| unheard-of(adjective, obscure, belief, exceptional, marvelous) |