Lau·ren·tia (lô-r
ĕn
sh
ə)
n. The North American craton which, according to the theory of plate tectonics, has existed since the Paleozoic Era and was once part of a supercontinent comprising present-day North America and Greenland.
[After the Laurentian Shield, the continental shield underlying northeast North America that forms the nucleus of the North American continent, after the SAINT LAWRENCE RIVER.]