mainstay

Từ điển Oxford Advanced Learner 8th

main·stay [mainstay mainstays] BrE [ˈmeɪnsteɪ] NAmE [ˈmeɪnsteɪ] noun usually singular ~ (of sth)
a person or thing that is the most important part of sth and enables it to exist or be successful
•He is the mainstay of our theatre group.
•Cocoa is the country's economic mainstay.
•Love songs form the mainstay of his act.

• Từ đồng nghĩa / Synonyms:
  anchor, keystone, backbone, linchpin, lynchpin, pillar