The word masturbation is believed to derive from either the Greek word mezea (μεζεα, "penises") or the Latin manus ("hand") and the Latin turbare ("to disturb"). A competing etymology based on the Latin manu stuprare ("to defile with the hand") is said by the Oxford English Dictionary to be an "old conjecture". The esoteric and little-used synonym manustupration is similarly derived from manus stuprare.
While "masturbation" is the medical term for this practice, many other terms and expressions are in common use. "Onanism" is a term with religious roots. In the vernacular, terms such as "pleasuring oneself", "wanking", and "jerking off" are common. See masturbate in Wikisaurus for many others.