- rheum australe
- root cause
- red clover
- red coral
- rosebay willowherb
- repent
- rocket scientist
- rocket range
- raymond b. cattell
- red phalarope
- rock python
- rock polypody
- rattle_top
- rose oil
- roquefort dressing
- Rocky Mountain bee plant
- rocket base
- rhubarb rhizome
- rhone_alpes
- rhubarb pie
- Rheum palmatum
- regressiveness
- rattlesnake plantain
- rosebud cherry
- Rapateaceae
- retail chain
- resale
- resident control program
- resident pharmacist
- repeating decimal
- regular hexagon (mathematics)
- regular octagon (mathematics)
- royal mast
- royally
- royal fern
- royal insignia
- rollback
- regulatory offence
- regulatory offense
- Rhiptoglossa
- reabsorption
- regeneration
- Rhodymenia
- robert a. heinlein
- reversible magnetic process
- reversible arrest
- reversible colloid
- reversibility of mutation
- reversible inactivation
- reversible counter