What does "iguana" mean?

Iguana: Any species of the genus Iguana, a genus of large American lizards of the family Iguanidæ. They are arboreal in their habits, usually green in color, and feed chiefly upon fruits. Note: The common iguana (I. tuberculata) of the West Indies and South America is sometimes five feet long. Its flesh is highly prized as food. The horned iguana (I. cornuta) has a conical horn between the eyes.