| impaired(adjective, poor, inferior, deficient, substandard) |
| impracticable(stupid, idle, trivial, incompetent, insufficient) |
| impractical(stupid, idle, trivial, incompetent, insufficient) |
| improper(adjective, inadequate, useless, inappropriate, unhealthy) |
| in vain |
| inane(adjective, slight, value, small, silly) |
| inapplicable(adjective, inadequate, useless, inappropriate, unhealthy) |
| inappropriate(adjective, inadequate, useless, unhealthy, shameful) |
| incidental(adjective, slight, small, unimportant) |
| incompatible(adjective, inadequate, useless, inappropriate, unhealthy) |
| incompetent(weak, stupid, idle, useless, impractical) |
| incongruous(adjective, inadequate, useless, inappropriate, unhealthy) |
| incorrect(adjective, inadequate, useless, inappropriate, unhealthy) |
| inefficient |
| ineligible(unfit, worthless, unworthy, undeserving) |
| inept(weak, stupid, idle, useless, incompetent) |
| inexpedient(adjective, inadequate, useless, inappropriate, unhealthy) |
| infelicitous(adjective, inadequate, useless, inappropriate, unhealthy) |
| inharmonious(adjective, inadequate, useless, inappropriate, unhealthy) |
| irrelevant(slight, small, unimportant) |