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

This helped transform the instrument, typically associated with Sunday church services, into a mainstay of contemporary pop instrumentation. —Paul Grein, Billboard, 14 July 2025

Today, with the S&P 500 Index funds a mainstay, such a shift could last a long time. —John S. Tobey, Forbes.com, 14 July 2025

Puckett, a San Diego music mainstay for much of the 1960s, still leads a band called The Union Gap. —George Varga, San Diego Union-Tribune, 13 July 2025

Scoop up mainstays, including the Levi’s Ribcage jean, Madewell’s high-neck tank top in soft cotton, or Good American’s easy pullover. —Kristina Rutkowski, Vogue, 8 July 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