- mainstay (of something)
a person or thing that is the most important part of something and enables it to exist or be successful 支柱;中流砥柱 He is the mainstay of our theatre group. 他是我们剧组的台柱。 Cocoa is the country's economic mainstay. 可可是这个国家的经济支柱。 Love songs form the mainstay of his act. 情歌是他表演的主体。