lynchpin meaning and definition

LYNCHPIN noun

Definition of lynchpin (noun)

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"
   • synonyms: anchor, backbone, keystone, linchpin, mainstay
2. pin inserted through an axletree to hold a wheel on
   • synonyms: linchpin