allopathic
Pejorative retronym. First invented by homeopaths trying to poke fun at orthodox medicine in the 1800s, the term gained new life in the 20th Century as a retronym to distinguish medical doctors (MDs) from osteopathic physicians (DOs).
"Allopathic? Bah! That allopath will feel my wrath," said the homeopath, receiving a spongebath.