Highway, n.
A road or way open to the use of the public; a main road or thoroughfare.
Syn. -- Way; road; path; course.
Shades of meaning
Fernald has no entry of its own for highway; he lists it under way.
Where he writes about it:
A road may be private; a highway or highroad is public, highway being a specific name for a road legally set apart for the use of the public forever; a highway may be over water as well as over land. — from way