crucibulum.

Uncertain. Suffixed with -bulum (“suffix for instruments or containers”), but with an uncertain base. Generally, crux (“a cross”) or its derivative verb, cruciō (“to crucify, to torture”), are cited as the base term; however, the semantic difference between these terms and crucibulum has led to many rejecting the theory. Yet still, a semantic relation from Latin cruciō (“to torture”) and Italian crogiolare (“to simmer, to cook slowly”) should be observed. The Etymological Dictionary of Latin and the other Italic Languages has no entry for this term, and Merriam-Webster rejects an etymological connection to crux except for possible influence. EtymOnline suggests a possible connection to Middle High German kruse (“earthen pot”), as the original crucibula were also constructed using earthen materials. The sense for 'night lamp' is often cited as the original definition of the term, which may suggest an etymology not connected to metallurgy if it does indeed predate the metallurgical instrument. Compare also Vulgar Latin *cruceolus, from which comes Old French croisuel and French creuset, as well as many other Romance terms for 'oil lamp' or 'crucible.'