- Bunyakovskiǐ inequality
- Bunyoro-Kitara Kingdom
- buoyage
- buoyancy
- buoyancy force
- buoyant
- buoyant jet
- buoyant riser unit
- buoyant tower
- bupirimate
- buprestid beetle
- buprofezin
- Buqu River
- bur
- Buraku Liberation Movement
- Burali
- Burali Forti
- Burali-Forti
- Burali-Forti paradox
- Burang Xian
- Buran spaceplane
- Burao
- burbling
- Burbury
- Burchfiel, Burrell Clark