Young Curly Brunette Girl Shows Off In The Mirrors With Angel Wings

The word angel in English is a fusion of the Old English word engel (with a hard g) and the Old French angele. Both derive from the Latin angelus which in turn is the romanization of the ancient Greek ἄγγελος (angelos), "messenger", which is related to the Greek verb ἀγγέλλω (angellō), meaning "bear a message, announce, bring news of" etc. The earliest form of the word is the Mycenaean a-ke-ro attested in Linear B syllabic script.
Philosophy
Philosophically, angels are "pure contingent spirits." According to Aristotle, just as there is a First Mover, so, too, must there be spiritual secondary movers. Thomas Aquinas (13th century) expands upon this in his Summa contra Gentiles and Summa Theologica.