| instinktive Reaktion | gut reaction |
| Instinktverhalten | instinctive behavior |
| Insertionsreaktion | insertion reaction |
| konstante Funktion | constant function |
| distinktives Merkmal | distinctive feature |
| stetige Funktion | continuous function |
| postmortale Erektion | death erection |
| sortierte Reaktionen | mixed reaction |
| Interaktion | interaction |
| Kettenreaktion | chain reaction |
| chemische Reaktion | chemical reaction |
| Intensivstation | intensive care unit |
| Institution | fixture institution |
| instanziieren | instantiate |
| Insinuation | insinuation |
| Inspiration | inspiration |
| Instinktbewegung | fixed action pattern |
| Insurrektion | insurrection |
| insinuieren | insinuate |
| insistieren | insist |