- ignoble: Lacking or having low moral standards; not noble in character
- imbibe: To take into the mind; absorb
- impassive: Devoid of any signs of emotion; expressionless
- imperious: Commanding, demanding; urgent
- ingratiate: To gain favor deliberately as so to gain oneself an advantage
- inherent: Relating to the essential character of something; built-in
- insensate: Lacking sensibility or depth of understanding; naive, foolish
- insolent: Insultingly arrogant; overbearing
- insular: Characteristic of an isolated, remote people, esp. with a narrow viewpoint
- insuperable: Incapable of being overcome or defeated
- inter: To bury
- interlocutor: One who participates in discussion
- internecine: Mutually destructive; equally devastating to both sides
- interregnum: A temporary halt of the typical operations of government or control
- intimation: A subtle, indirect hint
- intractable: Not easily manipulated or managed
- intransigent: Uncompromising; unyielding; refusing to abandon an extreme position
- intrepid: Fearless; extremely brave
- inundate: To cover with a flood; to overwhelm with a flood
- inveterate: Firmly established, esp. with respect to a habit or attitude
- irascible: Easily agitated or angered; hot-tempered
- ironic: Contrary or opposite of what was expected
- irreverent: Disrespectful in a gentle or humorous way
- itinerant: Wandering from place to place (like a nomad); unsettled