Difference between Linchpin and Mainstay

LINCHPIN vs MAINSTAY: NOUN

A central cohesive source of support and stability
A locking pin inserted in the end of a shaft, as in an axle, to prevent a wheel from slipping off.
A central cohesive element.
A pin inserted in the spindle of the axle of a vehicle to prevent the wheel from slipping off. Also axle-pin.
A pin used to prevent the wheel of a vehicle from sliding off the axletree.
A pin inserted through holes at the end of an axle, so as to secure a wheel
A central cohesive source of stability and security; a person or thing that is critical to a system or organisation.
Pin inserted through an axletree to hold a wheel on

The forestay that braces the mainmast
A prominent supporter
A chief support.
A strong rope that serves to steady and support the mainmast of a sailing vessel.
Plural All the stays which give support to the main lower mast, maintopmast, and maintopgallantmast.
The rope which secures the head of the mainmast of a vessel forward.
2. Chief support; main dependence: as, their mainstay is fishing.
The stay extending from the foot of the foremast to the maintop.
Main support; principal dependence.
A stabilising rope from the top of the mainmast to the bottom of the foremast.
A central cohesive source of support and stability

Mainspring, Hinge, Crux, Pillar, Key, Hub, Part, Crucial, Fulcrum, Keystone, Cornerstone, Anchor, Mainstay, Backbone, Lynchpin

Thrust, Essential, Mainstream, Fulcrum, Bedrock, Thorn, Hub, Keystone, Cornerstone, Staple, Anchor, Pillar, Lynchpin, Backbone, Linchpin

Pivot, Hinge, Crux, Pillar, Key, Hub, Part, Crucial, Fulcrum, Keystone, Cornerstone, Anchor, Mainstay, Backbone, Lynchpin

Thrust, Essential, Mainstream, Fulcrum, Bedrock, Thorn, Hub, Keystone, Cornerstone, Staple, Anchor, Pillar, Lynchpin, Backbone, Linchpin

Mainstay provides business value services to clients worldwide.
Pulse oximetry is the mainstay of respiratory monitoring.
This Hawaiian food mainstay boasts two Oahu locations.
Dried salmon was the mainstay of their diet.
Kylo Ren, and a mainstay of war culture.
Poles are a mainstay in the fishing world.
He was mixing Lion beer with Mainstay brandy.
Inclusive Youth Participation in Politics Mainstay to Achieving Peace Inclusive Youth Participation in Politics Mainstay to Achieving Peace Written by Yolanda Chitsanzara.
Mainstay Suites is a daily or extended See more of Mainstay Suites Extended Stay Hotel Casa Grande on Facebook.
Mainstay Parks Pale, a beer exclusive to Parks on Tap by Mainstay Independent Brewery.