| Term | Definition |
| idee fixe | A fixed idea; persistent or obsessive idea. |
| imprimatur | Sanction or approval; support. |
| inchoate | Incipient; lacking order; not yet completed. |
| indigent | Impoverished. |
| inimical | Harmful; hostile. |
| internecine | Mutually destructive; pertaining to conflict within a group. |
| interregnum | The time between rulers; any interruption in continuity. |
| intransigent | uncompromising; inflexible. |
| inveigle | to entice by flattery. |
| jejune | juvenile; uninformed; dull. |
| jeremiad | a prolonged lamentation or mournful complaint. |
| lachrymose | Mournful. |
| lacuna | A gap; a missing part. |
| lambaste | To beat; to censure. |
| latitudinarian | Having broad and tolerant views, esp. regarding religion. |
| leitmotif | A repetitive theme associated with a particular person or idea. |
| lenity | The quality of being mild and gentle towards others. |
| magniloquent | Grandiose (and pompous) in speech. |
| malinger | To pretend illness in order to shirk duties. |
| manumit | To release from slavery or servitude. |
| matutinal | pertaining to the morning. |
| maunder | To ramble meaninglessly; to wander aimlessly. |
| mephitic | Offensive to the noise; noxious. |
| minatory | Menacing; threatening. |
| moiety | An indefinite portion. |
| myrmidon | A person who executes without question or scruple a superior's orders. |