| Noun | 1. | Saint Lawrence River - a North American river; flows into the Gulf of Saint Lawrence and the North AtlanticCanada - a nation in northern North America; the French were the first Europeans to settle in mainland Canada; "the border between the United States and Canada is the longest unguarded border in the world" river - a large natural stream of water (larger than a creek); "the river was navigable for 50 miles" | |