ORMC - Pacinian corpuscle
- Orthoptera
- orthoptic
- orthoptics
- orthoptist
- orthoptoscope
- Orthoreovirus
- Orthorexia nervosa
- orthorhombic
- orthorrhachic
- orthoscope
- Orthoscopic
- orthoscopic lens
- orthoscopy
- orthosis
- Orthosis, thoracolumbosacral (TLSO)
- orthostatic
- orthostatic albuminuria
- orthostatic dyspnea
- Orthostatic hypotension
- orthostatic intolerance
- orthostatic lines
- orthostatic proteinuria
- orthostatic tachycardia
- orthostatic tremor
- orthostatism
- orthostereoscope
- orthothanasia
- orthotherapy
- orthotic
- orthotic device
- orthotics
- orthotist
- orthotolidine
- orthotonos
- orthotonos position
- orthotonos, orthotonus
- orthotonus
- orthotopic
- orthotopic neobladder
- orthotopic transplantation