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

Isaac is also a mainstay on television screens, having appeared in series like Netflix's The OA (2016–2019) and CBS' Star Trek: Discovery (2017–2018). —Randall Colburn, EW.com, 30 Jan. 2025

The change marks the end of an era for the organization, which was created in 1997 by a former VH1 executive and became a mainstay on the cable network’s programming slate. —Jordan Valinsky, CNN, 29 Jan. 2025

Soderbergh and the screenwriter David Koepp—a fellow Hollywood mainstay—don’t tip their hands much about what, exactly, is going on until the film’s final moments. —David Sims, The Atlantic, 25 Jan. 2025

In Nordic countries, cross country skiing and biathlon are mainstays on television. —Tim Genske, Forbes, 21 Jan. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 2

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