noun.
Any of various usually large herbivorous lizards of the subfamily Iguaninae, often having a dorsal crest and found chiefly in tropical America.
The Century Dictionary and Cyclopedia
noun.
A large lizard of the warmer parts of America, of the genus Iguana; also, some similar lizard of a related genus.
noun.
[capitalized] The typical and leading genus of the family Iguanidæ.
the GNU version of the Collaborative International Dictionary of English
noun.
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.