homeopathy /hō′mē·op″əthē/ [Gk, homoios, similar, pathos, disease] , a system of therapeutics based on the theory that “like cures like.” The theory was advanced in the late 18th century by Dr. Samuel Hahnemann, who believed that a large amount of a particular drug may cause symptoms of a disease whereas moderate dosage may reduce those symptoms; thus some disease symptoms may be treated by very small doses of medicine. Compare allopathy. −homeopathic, adj.