lynchpin
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}]