Noah Webster's Dictionary 1. (n.) A melting pot for purifying metals; also a hardship that is a test and builder of character, as in a melting pot composed of some very refractory substance, as clay, graphite, platinum, and used for melting and calcining substances which require a strong degree of heat, as metals, ores, etc. 2. (n.) A hollow place at the bottom of a furnace, to receive the melted metal. 3. (n.) A test of the most decisive kind; a severe trial; as, the crucible of affliction.

Multi-Version Concordance Crucible (3 Occurrences) Psalms 12:6 The words of Jehovah are pure words; As silver tried in a furnace on the earth, Purified seven times. (See JPS) Proverbs 17:3 The heating-pot is for silver and the oven-fire for gold, but the Lord is the tester of hearts. (See RSV NIV) Proverbs 27:21 The crucible is for silver, and the furnace for gold; but man is refined by his praise. (WEB NAS RSV NIV)