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
• 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

Oprah Winfrey dubbed these pajamas one of her favorite things last year, which comes as no surprise, as the brand has been an Oprah’s Favorite Things list mainstay through the years. —Maggie Horton, PEOPLE, 31 Oct. 2025

Playing in loud matches at big tournaments is likely to be a mainstay of Fonseca’s career. —George Ramsay, CNN Money, 31 Oct. 2025

Among those participating are Scorsese mainstays Robert De Niro and Leonardo DiCaprio, who, between them, starred in 15 of the director’s movies (and counting). —Graham Hillard, The Washington Examiner, 31 Oct. 2025

And daytime Halloween costume mainstays The Talk and The Real have ended their runs. —Hilary Lewis, HollywoodReporter, 31 Oct. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 2

Rhymes for mainstay

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

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