| REP | replication protein; rest-exercise program; retrograde pyelogram; roentgen equivalent-physical |
|---|---|
| rep | let it be repeated [Lat. repetatur]; replication; roentgen equivalent-physical |
| RKY | roentgen kymography |
| RU | radioulnar; rat unit; reading unit; residual urine; resin uptake; resistance unit; retrograde urogra... |
| x-rays | roentgen rays |