Mummy  A mummy is a dead human or an animal whose skin and organs have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or lack of air, so that the recovered body does not decay further if kept in cool and dry conditions. Some authorities restrict the use of the term to bodies deliberately embalmed with chemicals, but the use of the word to cover accidentally desiccated bodies goes back to at least 1615 AD (see the section Etymology and meaning). Mummies of humans and animals have been found on every continent, both as a result of natural preservation through unusual conditions, and as cultural artifacts. Over one million animal mummies have been found in Egypt, many of which are cats. Many of the Egyptian animal mummies are sacred ibis, and radiocarbon dating suggests the Egyptian Ibis mummies that have been analyzed were from time frame that falls between approximately 450 and 250 BC. In addition to the mummies of ancient Egypt, deliberate mummification was a feature of several ancient cultures in areas of America and Asia with very dry climates. The Spirit Cave mummies of Fallon, Nevada in North America were accurately dated at more than 9,400 years old. Before this discovery, the oldest known deliberate mummy was a child, one of the Chinchorro mummies found in the Camarones Valley, Chile, which dates around 5050 BC. The oldest known naturally mummified human corpse is a severed head dated as 6,000 years old, found in 1936 AD at the site named Inca Cueva No. 4 in South America. The English word "mummy" is derived from medieval Latin "mumia", a borrowing of the medieval Arabic word "mūmiya" (مومياء) and from a Persian word "mūm" (wax), which meant an embalmed corpse, and as well as the bituminous embalming substance, and also meant "bitumen". The Medieval English term "mummy" was defined as "medical preparation of the substance of mummies", rather than the entire corpse, with Richard Hakluyt in 1599 AD complaining that "these dead bodies are the Mummy which the Phisistians and Apothecaries doe against our willes make us to swallow". These substances were defined as mummia. The OED defines a mummy as "the body of a human being or animal embalmed (according to the ancient Egyptian or some analogous method) as a preparation for burial", citing sources from 1615 AD onward.