| FRAT | free radical assay technique |
|---|---|
| ORS | olfactory reference syndrome; oral rehydration solution; oral surgery, oral surgeon; Orthopaedic Res... |
| RAD | radial artery catheter; radiation absorbed dose; radical; radiography or radiographic; reactive airw... |
| rad | radiation absorbed dose; radial; radian; radical; radius; root [Lat. radix] |
| RND | radical neck dissection; radionuclide dacryography; reactive neurotic depression |