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From our dictionary:
em•py•re•an
(em"pu-rE'un, -pI-, em-pir'E-un, -pI'rE-),
—n.
the highest heaven, supposed by the ancients to contain the pure element of fire.
the visible heavens; the firmament.
(em"pu-rE'un, -pI-, em-pir'E-un, -pI'rE-),
—n.
the highest heaven, supposed by the ancients to contain the pure element of fire.
the visible heavens; the firmament.
—adj.
empyreal.