| Term | Definition |
| invective | abuse |
| invert | turn upside down/inside out |
| inveterate | deep-rooted; habitual |
| invidious | designed to create ill will or envy |
| inviolability | security from being destroyed corrupted or profaned |
| invoke | call upon;ask for |
| iota | very small quantity |
| irascible | irritable; easily angered |
| irksome | annoying |
| irreconcilable | incompatable; not able to be resolved |
| irreparable | not able to be corrected or repaired |
| irrepressible | not able to be restrained |
| irresolute | uncertain how to act |
| irreverent | lacking proper respect |
| irrevocable | unalterable |
| itinerant | wandering/traveling |