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 of mainstay

• anchor
• backbone
• pillar
• 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

Though there is much in the circumstance that merits applause, the mainstay of the effort was not to provide a positive mathematical proof per se, but instead to discover a counterexample that undercuts a prevailing conjecture regarding the solution to the thorny problem. —Lance Eliot, Forbes.com, 26 May 2026

Linney, an alum with deep ties to the program, tells students to expect a continuation of the strong teaching that has been a mainstay, including helping students identify their place in the world as artists. —Caitlin Huston, HollywoodReporter, 25 May 2026

Long a refrain of strident progressives and good-government reformers, accusations that political rivals are self-dealing or bought by special interests have become a mainstay of Democratic primaries. —Matt Brown, Fortune, 25 May 2026

While not as central as some of the other more coastal hotels in the area, the Marina District location puts it only about a 10- to 15- minute drive to most of the city’s mainstays, and rideshares are easy to grab from the hotel every hour. —Condé Nast, Condé Nast Traveler, 24 May 2026

Word History

First Known Use

15th century, in the meaning defined at sense 2

Rhymes for mainstay

• airway
• allay
• archway
• array
• ashtray
• assez
• astray
• aue
• away
• ballet
• belay
• beltway

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