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

But on Sunday, every order at the San Fernando Valley mainstay was served with a side of heartbreak as the restaurant marked its final day of business. — Carlos De Loera, Los Angeles Times, 10 Aug. 2026

Her feathery upper pitch, a mainstay on past records, is less constant. — Stephen Kearse, Pitchfork, 7 Aug. 2026

But kebabs are joined by a variety of stews, salads and eggplant dishes that are mainstays of Persian cooking. — Colin Wrenn, Denver Post, 5 Aug. 2026

The stickers were a mainstay of parking enforcement for decades in the city before the City Council nixed them in 2011. — Evan Simko-Bednarski, New York Daily News, 5 Aug. 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