noun
highway; main road; the right path
Refers to a major road or the correct, proper way, often used metaphorically for the right course of action.
この道は昔、本道として使われていた。
This road was once used as the main highway.
彼はついに本道に戻った。
He finally returned to the right path.
noun
internal medicine (traditional Chinese medicine)
Specialized term in the context of traditional Chinese medicine, referring to internal medicine as opposed to surgery or other branches.
See also: 内科 (ないか)
漢方では、本道は内科を指す。
In Kampo medicine, 本道 refers to internal medicine.