route vs causeway

route and causeway both are nouns.

Word	Noun	Adjective	Verb	Adverb
route	Yes	No	Yes	No
causeway	Yes	No	Yes	No

As nouns, causeway is a hyponym of route; that is, causeway is a word with a more specific, narrower meaning than route:

route (noun)	causeway (noun)
an open way (generally public) for travel or transportation	a road that is raised above water or marshland or sand
an established line of travel or access

route (verb)	causeway (verb)
send via a specific route	pave a road with cobblestones or pebbles
divert in a specified direction	provide with a causeway
send documents or materials to appropriate destinations