| implication | The conclusion that can be drawn from something although it is not explicitly stated | |
| imploring | To beg urgently or piteously, as for aid or mercy; beseech; entreat | |
| importune | To ask (someone) pressingly and persistently for or to do something | |
| impregnable | Not able to be defeated, overcome, or captured; very strong | |
| imprimatur | A person's acceptance or guarantee that something is of a good standard | |
| impromptu | Done without being planned, organized, or rehearsed | |
| impudence | The quality of being impudent; not showing due respect for another person | |
| impugn | To dispute the truth, validity, or honesty of a statement or motive; call into question | |
| inalienable | Not subject to being taken away from or given away by the possessor | |
| inane | Lacking sense or meaning; silly | |