The pivotal text for contemporary angel studies, being formally titled A dictionary of angels, including the fallen angels. (NY : Free Press, 1967) by Gustav Davidson. Includes alphabetic breakdown of angel lore from numerous traditions, both Eastern and Western and includes images, diagrams and tables on the angelic hierarchy from a thousand years of studies on the subject (for example, for scans of the scripta angelica, see http://www.sarahsarchangels.com/archangels/scripts.html). The varied names of angels, as beings, are also considered from culture to culture : 'mal'ach' in Hebrew, 'angrias' in Sanskrit, 'angaros' (courier) in Persian or 'angelos' in ancient Greek.1

Some terms :

Abdals : in Islamic lore, the 'substitutes', 70 mysterious spirits whose identities are known only to God alone, "When one of those entities dies (they are not immortal) another is secretly appointed in replacement' and it is through the operations and actions of these creatures that the world continues to exist.

Angels of Vengeance : These 12 angels were among the first formed at Creation, although according to official Catholic doctrine, all angels were formed simultaneously. Only five are mentioned by name : Saten'el, Michael, Uriel, Rappheal and Nathan'el.

Angel-year : according to Cornelius Agrippa and other occult philosophers, the year of an angel is 365 mortal years. Other occultists who worked on these and other angelic algebras at or around Agrippa's time included Robert Fludd, De Plancy (in his Dictionnaire Infernal - 1863), John Dee (court astrologer and diplomat for Queen Elizabeth) and of course Emanuel Swedenborg.

Balberith : ex-prince of the Order of Cherubim, now in Hell, Grand Pontiff and Master of Ceremonies, usually the one to countersign or notarize the signatures on any pact entered into between mortals and the Devil, and so referred to a 'Scriptor of Hell.'

Benad Hasche : 'daughters of G-d', female angels from the early mythos of Islam.

Eblis : 'despair', in Persian and Arabic lore, the equivalent to the Christian figure Satan. Once treasurer of the Heavenly Paradise, formerly named Azazel, before his fall from Grace.

Memunim : deputy angels, often malicious, involved in the magic of Cabala.

Some Quotes:

"It is well to bear in mind that all angels - whatever their state of grace - indeed, no matter how corrupt and defiant - are under God, even when, to all intents and purposes, they are performing under the direct orders of the Devil. Evil itself is an instrumentality of the Creator, who uses evil for his own divine, if unsearchable, ends." (xvii)

"God burned the angels of peace and truth, along with the hosts under them, as well as an entire legion of administering angels (the Yalkut Shimoni) for objecting to the creation of man - a project the Creator had his heart particularly set on and was determined to carry through, although later He reconsidered the venture, as we learn from Genesis 6 : 6." (xx)

"It should be pointed out however, that a fallen angel cannot repent - not, at least, in Catholic doctrine - for once an angel sins, he is 'fixed eternally in evil' and his mind, accordingly, can think evil only." See entry Abbadona, fallen angel, seraph, "the penitent one". (17)

"LUCIFER: ('light giver') - erroneously equated with the (supposedly) fallen angel (Satan) due to a misreading of Isaiah 14:12...an apostrophe which applied to Nebuchadnezzar, king of Babylon- It should be pointed out that the authors of the books of the Old Testament knew nothing of fallen or evil angels, and do not mention them, although at times as in Job 4:18, the Lord 'put no trust' in his angels and 'charged them with Folly', which would indicate that angels were not all they should be. The name Lucifer was applied to Satan by St. Jerome and other Christian Fathers." (146)
1Anacreon notes the Hebrew denotation is mal'ach (as opposed to malkah, meaning queen) originally meant messenger, was translated into Greek, and so spread to other languages. The resulting Greek word angelos (from which the Latin and English terms are derived) also means messenger. Daimon is a completely separate term, unrelated to communication.

Further Reading:

"Angels" from the New Catholic Encyclopaedia. http://www.newadvent.org/cathen/01476d.htm

Donald Barthelme. "On Angels," from Sixty Stories. (NY : 1990) Available online: http://www.it.cc.mn.us/literature/angel.html

Emanuel Swedenborg, 1688-1772. Concerning the earths in our solar system, which are called planets, and concerning the earths in the starry heaven; together with an account of their inhabitants, and also of the spirits and angels there. translated from the Latin. (London : Hindmarsh, 1787)

Angels & angelology in the Middle Ages / David Keck. (NY : Oxford, 1998)

Génies, anges et démons : Égypte, Babylone, Israël, Islam, peuples altaïques, Inde, Birmanie, Asie du sud-est, Tibet, Chine. (Paris : Éditions du Seuil, 1971)

The angels of light and the powers of darkness : a symposium by members of the Fellowship of S. Alban and S. Sergius / edited by E.L. Mascall. (London : The Faith Press, 1954)