radi - reci
- radiac
- radiac instrumentation
- radiac instruments
- radiacmeter
- radial
- radial admission
- radial air gap
- radial armature
- radial beam tube
- radial betatron oscillations
- radial circuit
- radial clearance
- radial commutator
- radial coordinate
- radial etch nonuniformity
- radial flow plasma etching reactor
- radial flow turbine
- radial flux power
- radial focusing
- radial force
- radial lead
- radial mode laser
- radial network
- radial stability
- radial subtransmission
- radial supply line
- radial tetrode
- radial transfer
- radial transmission line
- radially operated network
- radian
- radian frequency
- radian measure
- radiant energy
- radiant flux
- radiant flux density
- radiant heat
- radiant heater
- radiant heating
- radiant intensity
