- radiotelephone
- radiotelephonic
- raffia farinifera
- raffia ruffia
- ragusa
- ragwort
- raider
- raiding
- rail in
- rail line
- radio radiation
- radio set
- radial asymmetry
- radial tire
- radial vein
- radially symmetrical
- radiant energy
- radiant flux
- radiation pattern
- radio transmitter
- radio wave
- radiographer
- radiography
- radiolaria
- radiolocation
- radiologist
- radiometer
- radiopaque dye
- radiophone
- radiophonic
- radiophoto
- radioprotector
- radiotelegraph
- radiotelegraphy
- radiotelephony
- radiotherapy
- radiothorium
- radish
- radius of a circle
- radix
- radon
- raff
- raffaello santi
- raffaello sanzio
- raffia
- rafflesiaceae
- raftman
- rag
- rag gourd
- rag paper