- rotter
- Rotterdam
- Rotterdam Rules
- rotting edges syndrome of Apostichopus japonicus larvae
- rotund
- rotunda
- rotundity
- roturbo
- Rou
- Rouben Mamoulian
- Rouche
- Rouche theorem
- Rouché
- Rouché theorem
- Rouen
- Rouge
- rouge
- Rouge National Urban Park
- rough
- roughage
- rough approximation
- rough bluegrass
- rough calculation
- rough calculation curve
- rough coating