main drag vs main street

main drag and main street both are nouns.

Word	Noun	Adjective	Verb	Adverb
main drag	Yes	No	No	No
main street	Yes	No	No	No

As nouns, main street is a hypernym of main drag; that is, main street is a word with a broader meaning than main drag:

main drag: the main street of a town or city
main street: street that serves as a principal thoroughfare for traffic in a town

Other hypernyms of main drag include high street.

main drag (noun)	main street (noun)
the main street of a town or city	street that serves as a principal thoroughfare for traffic in a town