| Infusion | infusion |
| Konfusion | bewilderment |
| Diffusion | diffusion |
| Fusion | fusion merger |
| Intrusion | intrusion |
| Illusion | illusion |
| Inklusion | inclusion |
| Invasion | invasion |
| Infektion | infection |
| Inflation | inflation |
| Kernfusion | nuclear fusion |
| Allusion | allusion |
| Indusium | Induan |
| Inversion | anastrophe |
| Intension | tenseness |
| Ingestion | ingestion |
| Induktion | induction electromagnetic induction mathematical induction |
| Intuition | intuition |
| Einfügen | interposition |
| einfügen | insert |