EMPYR'EAL, adjective [Latin empyroeus; from Gr. fire.] 1. Formed of pure fire or light; refined beyond aerial substance; pertaining to the highest and purest region of heaven. Go, soar with Plato to the empyreal sphere. 2. Pure; vital; dephlogisticated; an epithet given to the air, or rather gas, now called oxygen.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI