Linchpin vs Axle - What's the difference?
linchpin | axle |
a pin inserted through holes at the end of an axle, so as to secure a wheel
(figuratively) a central cohesive source of stability and security; a person or thing that is critical to a system or organisation.
The pin or spindle on which a wheel revolves, or which revolves with a wheel.
A transverse bar or shaft connecting the opposite wheels of a car or carriage; an axletree.
An axis; as, the Sun’s axle.