- osculating tangent
- osculating tetrahedron
- osculation
- osculation circle
- osculation plane
- osculation point
- osculation process
- osculatory interpolation
- osculum
- OS detection
- Oseam
- Oseberg Ship Burial in Norway
- Oseen
- Oseen approximation
- Osei Bonsu
- oseillating rod type seed-metering device
- OSEK
- oseltamivir
- Osgood
- Osgood and Schramm's model
- Osgood theorem
- Osgood uniqueness condition
- Osh
- Oshana Region
- Oshawa