radi - reac
- radial air gap
- radial armature
- radial component
- radial diffusion
- radial distribution
- radial field
- radial flow fan
- radial lamination
- radial line system
- radial network
- radial scan
- radial steering wheelset
- radial system of ventilation
- radial temperature distribution
- radial ventilating duct
- radial ventilation
- radial-axial turbine
- radial-beam tube
- radial-blade blower
- radially magnetized
- radially operated network
- radially symmetric
- radian frequency
- radian measure
- radiance
- radiance of a surface
- radiant
- radiant absorption
- radiant ceiling heating
- radiant density
- radiant efficiency
- radiant emittance
- radiant energy
- radiant energy density
- radiant exitance
- radiant flux
- radiant flux density
- radiant heat
- radiant heat exchange
- radiant heat therapy
