- retinoscope
- retinoscopy
- retinula
- retinyl palmitate
- retinyl palmitate; vitamin A palmitate
- Retire
- retired servicemen medical insurance
- retired servicemen old-age insurance
- retirement
- retirement age
- retirement syndrome
- retirement system
- Retirement System for the Employees of Public Institutions
- Retiro Park
- retort
- retouching
- retrace
- retract
- retractable enclosure
- retractable undercarriage test
- retracted confession
- retractibility
- retractible
- retractible neighborhood
- retracting deformation