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
• buttress
• dependence
• dependance
• pillar
• reliance
• 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

He's been a mainstay in the Cubs bullpen and has been extremely reliable when manager Craig Counsell has needed him. —Andrew Wright, MSNBC Newsweek, 22 June 2025

Lacroix and Kirkland flavored sparkling water are mainstays in our home. —Scott Kramer, Forbes.com, 22 June 2025

While the famed annual show has now become a mainstay in the NFL, at the time it had never been done before other than during the Super Bowl. —Katie Mannion, People.com, 22 June 2025

Farming, however, provided the impetus for dogs to become a mainstay in communities that had been growing increasingly advanced. —Jack Knudson, Discover Magazine, 18 June 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