indistinct indisposition indispensable indigestion indifferent indicator indefinite incurable incur incubate incredible incorporate incorrupt incoordinate incontinence inconsistent incompatible incline inclination incite incentive incitant incision incidence incessant incense inborn inappetence impulse impudent imprudent improper imprison imprint impose implicit implication impetus implement implant impersonal impatient imperative impel impede impatience impartial impair impact immunotherapy immunoregulation immunology impart immunodeficiency immortal imminent immerse immense immature immemorial immediate immeasurable imitation imitate imbibe imaginative imagination imaginary imaginable image illustration illustrate illusion illogical illuminate ileus illiterate illegible illegal ileum ileocolic ignore ignorant ignorance ignite idle idiot idiopathic idiomatic idiom ideology identity identification identical ideological identify icy icteric ivory item itch isotope ischemia irritate irrigation irrigate irreversible irresistible irrelevant irrational irradiation ion iodine involuntary invite invitation invoke investment invest invasion invigorate invalid invade intuition intrude intrinsic intravascular intravenous intramuscular intolerant intervene intimate intestine intersperse interrogative interpret interplay interpretation intermittent interposition intermediate interlace interim interferon interference interfere interface interaction intercellular interact intentional intention intensive intensity intense intend intelligible intensify intelligent intelligence integrate intellectual integral intellect intact insurance insure insult insulate insufficiency instrument instruction instruct institution institute instinct inspection instillation instant install inspire inspect insomnia insoluble insolation insidious insert inseminate insecticide inscribe insanitary insane inquiry inquire inpatient inorganic inoperable inoculate innovative innocuous innate inn injustice initiative initiate innocent inherit initial inhibit inherent inhale ingredient ingest infuse infrared inflict inflation inflammatory inflammation inflammable inflame infinity infinitive infinite infiltrate infest infertile inferior inference infectious infarct inevitable inertia industrious indulge induction induce indomitable