/ˈmeɪnsteɪ ||; ˈmenˌste/noun [C] a person or thing that is the most important part of sth, which makes it possible for it to exist or to be successful 主要依靠；主要支柱；台柱；靠山: Cocoa is the mainstay of the country's economy. 可可粉是该国经济的支柱。