mainstay

noun

main·​stay ˈmān-ˌstā 

plural mainstays

1

a

: a crucial or key part of something

Fish is the mainstay of their diet.

Tourism is a mainstay of the city's economy.

The mainstay of treatment for chronic hives of unknown origin is antihistamine medications.

—Mayo Clinic Health Letter

b

: someone or something that is a principal or reliable support or resource

Tourism is one of the city's economic mainstays.

Her immense pride in him and unquestioning support were among the few mainstays in his life.

—Robert V. Remini

2

: a ship's stay (see stay entry 1 sense 1) extending from the maintop forward usually to the foot of the foremast

Synonyms

• anchor
• buttress
• dependence
• dependance
• pillar
• reliance
• standby

Examples of mainstay in a Sentence

Fish is a mainstay of their diet.

My mother has always been the mainstay of our family.

Recent Examples on the Web

Carpenter’s album Short n’ Sweet has been a chart mainstay in the U.K. since its release in August 2024. —Thomas Smith, Billboard, 10 Feb. 2025

Meanwhile, the Chiefs have also been a mainstay in recent Super Bowls, appearing in their fifth championship game in the last six seasons. —Stuart Dyos, Fortune, 9 Feb. 2025

What’s one thing that is a mainstay in your salads? —Jessica Radloff, Glamour, 7 Feb. 2025

Sid Grams, who has been a mainstay in Hutchinson grocery stores long enough to become almost legendary, is retiring from the retail business after 40 years of service. —Kay Johnson, Twin Cities, 6 Feb. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 2

Kids Definition

mainstay

noun

main·​stay -ˌstā 

1

: a large strong rope running from the maintop of a ship usually to the foot of the foremast

2

: a chief support

the mainstay of the family