Nutritious—A substance which feeds the body.
Obesity—Excess of fat or flesh.
Obstetrics—The science of midwifery.
Oculus—The eye.
Œsophagus—The tube leading from the throat to the stomach.
Optic Nerve—The nerve which enters the back part of the eye.
Organic—Having organs.
Os—Mouth; used as mouth of womb.
Ostalgia—Pain in the bone.
Otitis—Inflammation of the ear.