Word of the Day:

1 : a locking pin inserted crosswise (as through the end of an axle or shaft)

2 : one that serves to hold together parts or elements that exist or function as a unit

A matching DNA sample was the linchpin in the murder case.

"Although ties to the EU remain its economic linchpin, the country has shifted economic and foreign policy toward its old Ottoman holdings in the Mideast and ethnic brethren in Central Asia." -- From an article by Joel Kotkin in Newsweek, October 4, 2010

More example sentences

"There was the good old custom of taking the linch-pins out of the farmers' and bagmens' gigs at the fairs, and a cowardly blackguard custom it was." That custom, described by British writer Thomas Hughes in his 1857 novel Tom Brown's School Days, was "blackguard" indeed. The linchpin in question held the wheel on the carriage and removing it made it likely that the wheel would come off as the vehicle moved. Such a pin was called a "lynis" in Old English; Middle English speakers added "pin" to form "lynspin." Modern English speakers modified it to "linchpin" and, in the mid-20th century, began using the term figuratively for anything as critical to a complex situation as a linchpin is to a wagon.