Relating to or composed of ether; extremely light, airy, or delicate; heavenly or spiritual in nature.
Variant spelling of ethereal, from aether plus -ial suffix. Both 'etherial' and 'ethereal' exist, with ethereal becoming standard modern spelling.
The spelling 'etherial' shows English's historical inconsistency — for centuries both spellings competed, and you can date texts by which one they use, with 'ethereal' winning out only in modern standardized English.
Complete word intelligence in one call. Free tier — 50 lookups/day.