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
Cite this Entry
“Mainstay.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mainstay. Accessed 8 Aug. 2026.
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