The most common of several names or phrases used in the Old Testament to refer to disobedient angels is "familiar spirit." It is used sixteen times and refers to devils who can be summoned by a variety of names to provide (or pretend to) supernatural services (predicting the future, contacting the dead, etc.). In the New Testament, the most common term for such spirits is "devils," which is used fifty-one times.
Before we begin our list of synonyms for devils, it is interesting to note that Jewish tradition assigns personal names to two spirits they believe are the most powerful demons. The king of all the devils is called Ashmodai or Sammael. The queen of the female spirits (they believe spirits have a sex) is named Lilith. She is a demon of the night who goes after anyone who sleeps alone in a room. The KJV Bible, other than "Satan," does not reveal the personal names of any demons.
Please note that not all Scriptural references to a particular term or phrase for devils are given. Additionally, for some listings below, we have included in square brackets other potential translations of the Hebrew or Greek text.
Angels that sinned (2Peter 2:4).
Angels which kept not their first estate (did not stay righteous as created, Jude 1:6).
Devils (Leviticus 17:7, Deuteronomy 32:17, Matthew 10:8, 12:27 - 28, Mark 1:34, Revelation 18:2, etc.).
Evil angels (Psalm 78:49).
Evil spirit or spirits (Judges 9:23, 1Samuel 16:14 - 16, Luke 7:21, Acts 19:12 - 17, etc.).
Familiar spirits (Leviticus 19:31, 20:6, Deuteronomy 18:11, 1Samuel 28:9, etc.).
Foul [unclean, impure] spirit (Revelation 18:2).
Gods whom they knew not (Deuteronomy 32:17).
Legion (this is not a proper name, but rather the term used by the devils to designate several thousand of them possessing a single person, see Luke 8:30, Mark 5:9).
Lying [deceiving] spirit (1Kings 22:22 - 23, 2Chronicles 18:20).
Power of darkness [shadiness, obscurity, Luke 22:53, Colossians 1:13].
Prince of the kingdom of Persia (a reference to a powerful devil, Daniel 10:13).
Rulers of the darkness of this world (Ephesians 6:12).
Seducing [misleading, deceiving] spirits (1Timothy 4:1).
Spirit (1Kings 22:21).
Spirit of an unclean devil (Luke 4:33).
Spirit that now worketh in the children of disobedience (Ephesians 2:2).
Spirits in prison [guarded, caged, watched] who were disobedient (1Peter 3:19 - 20).
Spiritual wickedness [depravity, malice, plots] in high [celestial, heavenly] places (Ephesians 6:12)
The evil (the collective efforts of all the devils, John 17:15).
The spirits (Matthew 8:16, 12:45, Luke 10:20, 11:26).
Unclean spirit or spirits (Zechariah 13:2, Matthew 10:1, Mark 1:27, 3:11, Luke 4:36, Revelation 16:13, etc.).