crucible

Merriam-Webster's Word of the Day for January 14, 2012 is:

crucible • \KROO-suh-bul\  • noun
1 : a vessel in which metals or other substances are heated to a very high temperature or melted 2 : a severe test 3 : a place or situation in which concentrated forces interact to cause or influence change or development

Examples:
Living in the crucible that was Paris in the spring of 1968, Remi got to witness firsthand the angry confrontations between workers, students, and government.

"'Desire' -- it's the perfect name for Pedro Almodóvar's production company, the crucible for all his films including Law of Desire, the movie that helped make a star out of a young Spanish actor named Antonio Banderas." -- From a film review by Lawrence Osborne in Newsweek, October 3, 2011

Did you know?
"Crucible" looks like it should be closely related to the Latin combining form "cruc-" ("cross"), but it isn't. It was forged from the Medieval Latin "crucibulum," a noun for an earthen pot used to melt metals, and in English it first referred to a vessel of a very heat-resistant material (such as porcelain) used for melting a substance that requires a high degree of heat. But the resemblance between "cruc-" and "crucible" probably encouraged people to start using "crucible" to mean "a severe trial." That sense is synonymous with one meaning of "cross," a word that is related to "cruc-." The newest sense of "crucible" ("a situation in which great changes take place" -- as in "forged in the crucible of war") recalls the fire and heat that would be encountered in the original heat-resistant pot.