mainstay
UK[ˈmeɪnsteɪ]US[ˈmeɪnsteɪ]
n
a person or thing that is the most important part of something and enables it to exist or be successful
n
a rope or wire that supports the mainmast of a sailing ship
Morpheme Breakdown
main
stay
main
primary
stay
support
Etymology
the word 'mainstay' is a nautical compound originating in the late 15th century. it literally refers to the strong 'stay' (a supporting rope or cable) that secures the 'main' (the principal) mast of a ship, crucial for its stability. by the mid-17th century, this tangible concept of primary support was figuratively extended to any person or thing that serves as a chief source of strength and stability for an organization, system, or activity. the logic of the word perfectly bridges the physical and metaphorical, where the 'main' element provides the central strength, and the 'stay' provides the essential, sustaining support.
Analysis
Structure: main (primary) + stay (support)
main (from old english 'mægen' meaning strength, power, via middle english; functional role: adjective/attributive noun meaning chief or principal). stay (from old english 'stæg' meaning a rope supporting a mast, via middle english; functional role: noun meaning a support or prop).
Examples
agriculture remains the mainstay of the country's economy.
she has been the mainstay of the team throughout the difficult season.
the crew hurried to check the mainstay after the storm.