- ratchet
- rachitic pelvis
- rachitogenic diet
- retinitis
- rhinitis
- radiculitis
- riband
- ribaldry
- republican
- republican state
- republican river
- roast beef plant
- roister
- radical cure
- receiving perforator
- radio activity hazards
- ruddle
- robust
- robust fellow (said contemptuously)
- robust (fellow —said of a man in a contemptuous vein)
- reddrop_periflo mill
- radford ventilatory nomogram
- radial depth
- rotary drum process
- rotary engine
- rotary grater
- radialpalmar grasp
- redblooded
- radiate ligament
- radiate zone
- radiate lumen
- radio therapy
- radiation anaemia
- radiation decomposition
- radiation dose rate
- radioscan
- radioluscent stone
- radiofrequency drying
- radiommuno assay
- radiometer gauge
- rayleigh
- radiosodium space
- red arsenic
- royal automobile club
- raised bed
- raised
- rajmah
- rake out
- raleigh
- rallentando