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

Stoker’s research on Transylvanian folklore is primarily from Emily Gerard, whose work has continued to be a mainstay of English-language Transylvanian lore to this day. —Robert Eggers, HollywoodReporter, 17 Oct. 2025

The fashion set has just deployed a new fall jacket that could become a wardrobe mainstay for us all. —Leah Dolan, CNN Money, 17 Oct. 2025

But a mainstay for the Dallas defense is out for the foreseeable future, which is never good news. —Ryan Morik, FOXNews.com, 17 Oct. 2025

There are a few reliable mainstays of toddler life, though. —Elisabeth Sherman, Parents, 17 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