adjective.seeming to belong to or come from another world: otherworldly

• … the rise of a peaking full moon, which bathed the wild shore in an ethereal glow.
• … a wood thrush sang its ethereal song.

adjective.of, relating to, or suggesting heaven or the heavens

• White clouds veiled the sun, and a few ethereal rays came through.
• Students, to you 'tis giv'n to scan the heights / Above, to traverse the ethereal space, / And mark the systems of revolving worlds.

adjective.lacking material substance: immaterial, intangible

• The Web dwells in a never-ending present. It is—elementally—ethereal, ephemeral, unstable, and unreliable.
• … he imagined that … she was exhaling away, and that something of her ethereal substance was withdrawn with each lessening gleam of light.