Osteopath: An osteopathic physician who is a Doctor of Osteopathy (D.O.). In most US states, osteopaths must complete a course of study equivalent to that of an MD and are licensed to practice medicine. They may prescribe medication and perform surgery, and they often use manipulation techniques similar to chiropractics or physical therapy. Found on http://www.medterms.com/script/main/art.asp?articlekey=4683