A raptor that was taken from the wild in the fall of its first year, or a wild raptor that has not yet molted into its adult plumage. Found on http://www.americanfalconry.com/Glossary.html
(from the article `falconry`) ...has its own language, much of which is universal. A young hawk taken from a nest in the wild or bred in captivity is known as an eyas. A hawk ... Found on http://www.britannica.com/eb/a-z/p/25