main street is a noun meaning "street that serves as a principal thoroughfare for traffic in a town". It carries 2 recorded senses.
street that serves as a principal thoroughfare for traffic in a town
any small town (or the people who inhabit it); generally used to represent parochialism and materialism (after a novel by Sinclair Lewis)
“Main Street will never vote for a liberal politician”
Definitions, synonyms and semantic relations for main street come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.