✨📕 The NEWThe NEW Collegiate Dictionary, 12th Edition Over 5,000 words added — Buy Now! Collegiate DictionaryBuy Now!

Saint Lawrence Seaway

geographical name

waterway including a system of canals, locks, and dams in Canada and the U.S. in and along the Saint Lawrence River between Lake Ontario and Montreal

Browse Nearby Words

Cite this Entry

“Saint Lawrence Seaway.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Saint%20Lawrence%20Seaway. Accessed 1 Dec. 2025.

More from Merriam-Webster on Saint Lawrence Seaway

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!