persian for "animal". Used jokingly between friends; to be heyvoon (or to be heyvoon) is to be uncouth, grotesque, wild, licentious. Particularly used to describe someone eating in a rapid, messy or rude way. "heyvooning" is also said to indicate the act of being heyvoon. compare with sauvage. WARNING: Absolutely NOT for use in any sort of polite conversation with persians, as the term is very offensive.