| OI | utter a high-pitched cry, characteristic of pigs |
|---|---|
| OI | toiletry consisting of any of various substances resembling cream that have a soothing and moisturizing effect when applied to the skin |
| OI | semisolid preparation (usually containing a medicine) applied externally as a remedy or for soothing an irritation |
| OI | the parliament of the Republic of Ireland |