adj. Occurring in tropical America, i.e. the tropics of "the new world".
the GNU version of the Collaborative International Dictionary of English
adj. Belonging to, or designating, a region of the earth's surface which comprises most of South America, the Antilles, and tropical North America.
The Century Dictionary and Cyclopedia
In zoƶgeog., belonging to that division of the New World which is not Nearctic: specifically applied by Sclater to one of six prime divisions of the earth's surface, and including all of America which is south of the Nearctic region.
Word Usage
"The Caribbean slope is a major migration route; neotropical and altitudinal migrants comprise about 30% of the avifauna, particularly against the foothills."