| Ichth. | ichthyology |
| Icthyol. | icthyology |
| Ideol. | ideology, ideological |
| Idol. | idolatry |
| Illustr. | illustrated, illustration(s) |
| Imag. | imaginary, imagination |
| imit. | imitative |
| Immunol. | immunology |
| imp. | imperative |
| imperf. | imperfect |
| impers. | impersonal |
| impf. | imperfect |
| Impr. | impression(s) |
| Impr. | imprint |
| Impr. | improved |
| improp. | improper(ly) |
| Inaug. | inaugural |
| Inclos. | inclosure |
| Ind. | India(n) |
| ind. | indicative |
| ind. | indirect |
| Ind. | industry |
| indef. | indefinite |
| indic. | indicative |
| indir. | indirect |
| Industr. | industrial |
| Industr. Rel. | industrial relations |
| infin. | infinitive |
| infl. | influenced |
| Infl. | influence |
| Innoc. | innocence, innocent |
| Inorg. | inorganic |
| Inq. | inquiry |
| Inst. | institute, institution |
| instr. | instrumental |
| Instr. | instruction |
| int. | interjection |
| Intell. | intelligence, intelligent |
| Intellect. | intellectual |
| Interc. | intercourse |
| interj. | interjection |
| Interl. | interlude |
| Internat. | international |
| Interpr. | interpretation |
| interrog. | interrogative |
| intr. | intransitive |
| intrans. | intransitive |
| Intro. | introduction |
| Introd. | introduction, introductory |
| Inv. | inventory, inventories |
| Invent. | invention(s) |
| Invent. | inventory, inventories |
| Invertebr. | invertebrate, invertebrated |
| Invert. Zool. | invertebrate zoology |
| Investig. | investigation |
| Investm. | investment |
| Invoc. | invocation |
| Ir. | Irish |
| Irel. | Ireland |
| iron. | ironically |
| irreg. | irregular(ly) |
| Isa. | (in the Bible) Isaiah |
| Ital. | Italian |
