| FF | degree of fineness of abrasive particles; fat-free; father factor; fecal frequency; fertility factor... |
|---|---|
| REF | ejection fraction at rest; referred; refused; renal erythropoietic factor |
| RF | radial fiber; radio frequency; receptive field; regurgitant fraction; Reitland-Franklin [unit]; rela... |
| CRD | carbohydrate-recognition domain; chronic renal disease; chronic respiratory disease; child restraint... |
| CRT | cadaveric renal transplant; cardiac resuscitation team; cathode-ray tube; certified; Certified Recor... |