Dictionary.net

• a seaway involving the Saint Lawrence River and the Great Lakes that was developed jointly by Canada and the United States; oceangoing ships can travel as far west as Lake Superior

2006 - WordNet 3.0
By Princeton University

• a seaway involving the Saint Lawrence River and the Great Lakes that was developed jointly by Canada and the United States; oceangoing ships can travel as far west as Lake Superior

2011 - English Dictionary Database
By DataStellar Co., Ltd