Meaning of LYNCHPIN

WordNet Dictionary
	Definition:		[n]  pin inserted through an axletree to hold a wheel on [n]  a central cohesive source of support and stability; "faith is his anchor"; "he is the linchpin of this firm"
	Websites:
	Synonyms:		anchor, backbone, linchpin, linchpin, mainstay
	See Also:		pin, support