- responsibility
- rarefied
- recover
- religious movement
- roulette
- regulation
- risque
- relation
- remnant
- respiration
- ringlet
- revet
- respiratory quotient
- relative humidity
- rich
- rousing
- renunciation
- reductio ad absurdum
- romantic
- repel
- respect
- receptacle
- remedy
- raising
- rising
- recuperative
- recorder
- retrieve
- recoup
- resolving
- reasonably
- reflectivity
- religion
- rocket
- rhubarb
- resident
- regular
- romper
- reversible
- roller
- rickets
- rink
- rococo
- reproach
- revive
- roustabout
- roadman
- reel
- renascence
- rekindle