- An animal's horn capped at the open end, used to carry gunpowder.角制火药筒：在开口处加了盖的动物的角，用来装弹药
- ionophore
- ionophores
- ionosphere
- ion propulsion
- ion rocket
- ions
- -ions
- ion trap
- IOOF
- iota
- iotacism
- iotacisms
- iotas
- IOU
- IOUs
- -ious
- Iowa
- Iowa Central Community College
- Iowa City
- Iowa Lakes Community College-Estherville
- Iowa Lakes Community College-South
- Iowa River
- Iowas
- Iowa State University
- Iowa Wesleyan College