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

While Reese’s are a candy aisle mainstay, these Unwrapped Mini Trees are a new twist on an old favorite. —Melissa Locker, Southern Living, 5 Dec. 2025

Campbell has been a mainstay with the Cyclones since joining them back in 2015 after a successful stint with Toledo. —Nelson Espinal, MSNBC Newsweek, 5 Dec. 2025

Julian Clary’s the show’s mainstay, and it’s essentially built around him and the guest star. —Baz Bamigboye, Deadline, 5 Dec. 2025

The SeaBreeze quickly became a Westhampton mainstay, a place for all types who needed an affordable place to lay their heads in the South Fork’s gateway town. —Hannah Walhout, Travel + Leisure, 4 Dec. 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