[ 'kru:sɪb(ə)l ]
■ noun
1》 a container in which metals or other substances may be melted or subjected to very high temperatures.
2》 a situation in which people or things are severely tested, often interacting to produce something new: a relationship forged in the ~ of war.
Origin
ME: from med. L. crucibulum 'night lamp, ~', from L. crux , cruc- 'cross'.