Definition of Nearctic

Adjective: Nearctic ni'aa(r)k-tik

Of or pertaining to a region of the earth's surface including all of temperate and arctic North America and Greenland. In the geographical distribution of animals, this region is marked off as the habitat of certain species
"Therefore the threat to Nearctic migrants from habitat alteration cannot be general because most of them occur in two or more zoogeographic regions"