| Acronym | Definition |
|---|
| RIOS➣Remote Input Output System |
| RIOS➣Recycling Industry Operating Standard |
| RIOS➣Reactive Infinite-Order Sudden |
| RIOS➣Research Internships in Ocean Sciences (Rutgers University; New Brunswick, NJ) |
| RIOS➣Rhode Island Orchid Society |
| RIOS➣Respiratory Illness Opinion Survey (psychology) |