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

Finding the right partner for Mainoo, who has become a mainstay again under United’s new manager, will be vital to realising Carrick’s vision. —James McNicholas, New York Times, 2 June 2026

Vegas, meanwhile, has been a playoff mainstay since the expansion team arrived in 2017. —Tim Rohan, NBC news, 2 June 2026

Hennessy is a mainstay in hip hop, with its name used in the lyrics of more than 4,000 tracks and has a strong footprint in sports. —Jordan Valinsky, CNN Money, 1 June 2026

Also included are mainstays of podcast advertisements including the powder supplement maker AG1 and the robo-advisor pioneer Betterment as well as the online ticket marketplace SeatGeek. —Hugh Son, CNBC, 1 June 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