Mainstay

Mainstay

Noun · /ˈmeɪn.steɪ/

Definition

(Figurative) a person or thing on which something or someone depends most heavily for support or existence; the chief support or principal element of something; (Nautical, literal) the stay — a thick rope — that runs from the mainmast to the bow of a sailing vessel.

Origin

From main (principal, chief) + stay (a thick rope or wire supporting a mast, from Old Norse stag). The literal nautical meaning — the principal stay supporting the mainmast forward — gives the figurative meaning. The mainmast being the most important mast on the ship, and its stay being critical to keeping the mast upright, the mainstay became the figurative term for whatever most supports a system or person.