Linchpin - Definition
linchpin
n 1: a central cohesive source of support and stability; "faith
is his anchor"; "the keystone of campaign reform was the
ban on soft money"; "he is the linchpin of this firm" [syn:
anchor, mainstay, keystone, backbone, linchpin,
lynchpin]
2: pin inserted through an axletree to hold a wheel on [syn:
linchpin, lynchpin]