Plethora comes from a similar Greek word meaning "fullness." It was first used in English in the 16th century to describe a supposed medical condition marked by an excess volume of blood causing swelling and a reddish complexion. Later, the medical use of "plethora" was extended to indicate related medical conditions (such as an excess volume of bodily fluid or the red-skinned appearance of some newborns). These days, however, "plethora" is more often used in a general, non-medical sense, with the meaning "excess" or "abundance."