iguana

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various large tropical American lizards of the family Iguanidae, often having spiny projections along the back.

Century Dictionary and Cyclopedia

1. n. A large lizard of the warmer parts of America, of the genus Iguana; also, some similar lizard of a related genus. The best-known species is the tuberculated iguana, I. tuberculata, of the West Indies and South America. It attains a length of 5 feet or more, and presents a rather formidable appearance, but is inoffensive unless molested; it feeds upon vegetables, and its flesh is much used for food. The tail is very long, compressed, and tapering; a row of scales along the back is developed into a serrate crest or dorsal ridge; the head is covered with scaly plates; and the throat has a large dewlap. The iguana is of arboreal habits, spending much of the time in trees and bushes, basking in the sun. It is easily approached, and is often captured by means of a noose attached to a stick. Its coloration is variegated with brownish, greenish, and yellowish tints.
2. n. [capitalized] The typical and leading genus of the family Iguanidæ. It was formerly of great extent, but is now restricted to I. tuberculata (see above), and species closely related to it, such as the naked-necked iguana of South America, I. delicatissima, and the horned iguana of San Domingo, I. cornuta.

Wiktionary

1. n. Any of several members of the lizard family Iguanidae.
2. n. Any member of the genus Iguana.
3. n. A green iguana (Iguana iguana); a large tropical American lizard often kept as a pet.

GNU Webster's 1913

1. n. (Zoöl.) 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.

WordNet 3.0

1. n. large herbivorous tropical American arboreal lizards with a spiny crest along the back; used as human food in Central America and South America