- a large, arboreal lizard, Iguana iguana, native to Central and South America, having stout legs and a crest of spines from neck to tail.
- any of various related lizards of the genera Iguana, Ctenosaura, Conolophus, and Amblyrhynchus.
- either of two large tropical American arboreal herbivorous lizards of the genus Iguana, esp I. iguana (common iguana), having a greyish-green body with a row of spines along the back: family Iguanidae
- any other lizard of the tropical American family Iguanidae
- another name for leguaan
