St. Lawrence Seaway vs sea lane

St. Lawrence Seaway and sea lane both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. Lawrence Seaway	Yes	No	No	No
sea lane	Yes	No	No	No

St. Lawrence Seaway (noun)	sea lane (noun)
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	a lane at sea that is a regularly used route for vessels