from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The protocontinent of the Northern Hemisphere, a hypothetical landmass that according to the theory of plate tectonics broke up into North America, Europe, and Asia.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A supercontinent including most of the landmasses which make up today's continents of the northern hemisphere.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a hypothetical continent that (according to plate tectonic theory) broke up later into North America and Europe and Asia