The centre of any activity.
A solution that people will tend to use in the absence of communication, because it seems natural, special, or relevant.
A focus; a point at which rays of light or other radiation converge.
A feature that attracts particular attention.
A central cohesive source of stability and security; a person or thing that is critical to a system or organisation.
A pin inserted through holes at the end of an axle or shaft, so as to secure a wheel or shaft-mounted device.
To adopt as, or serve as, a central cohesive source of stability and security.