Moyna is a variant of Mona. Mona is a diminutive of Monica. There are several possible explanation of the origin of this name. I can be associated with the Greek word monos, meaning "alone, solitary", or it could be derived from the Latin monere "to advise". It has been used since the 18th century. The most famous bearer of the name was Saint Monica, the patron saint of married women. It was widely popularized by the character name in the TV show Friends. In some languages, Mona can be used as a masculine given name as well.