| suspect(extraordinary, amazing, incredible) |
| thin(extraordinary, amazing, incredible) |
| thoughtless(adjective, careless, stupid, unthinking, unobservant) |
| too much(expression, extraordinary, amazing, dubious, astonishing) |
| unbelievable(adjective, extraordinary, amazing, incredible) |
| unconvincing(extraordinary, amazing, incredible) |
| underachieving(adjective, dull, simple, limited) |
| undiscerning(careless, stupid, unthinking, obtuse, unperceptive) |
| unimaginable(extraordinary, amazing, incredible) |
| unreasonable(careless, stupid, unthinking, obtuse, unperceptive) |
| unreasoning(careless, stupid, unthinking, unintelligent, obtuse) |
| unreflective(careless, stupid, unthinking, obtuse, unperceptive) |
| unsubstantial(extraordinary, amazing, incredible) |
| unteachable |
| unthinkable(extraordinary, amazing, incredible) |
| vacuous(adjective, careless, silly, stupid, empty) |
| weak(dull, simple, extraordinary, limited, amazing) |
| witless(careless, silly, stupid, unthinking, unintelligent) |
| wrongheaded |
| yo-yo(adjective, dull, simple, limited) |