|Easton's Bible Dictionary|
Frequently mentioned in Scripture. It is called in Hebrew maphteah, i.e., the opener (Judges 3:25); and in the Greek New Testament kleis, from its use in shutting (Matthew 16:19; Luke 11:52; Revelation 1:18, etc.). Figures of ancient Egyptian keys are frequently found on the monuments, also of Assyrian locks and keys of wood, and of a large size (Comp. Isaiah 22:22).
The word is used figuratively of power or authority or office (Isaiah 22:22; Revelation 3:7; Revelation 1:8; Comp. 9:1; 20:1; Comp. also Matthew 16:19; 18:18). The "key of knowledge" (Luke 11:52; Comp. Matthew 23:13) is the means of attaining the knowledge regarding the kingdom of God. The "power of the keys" is a phrase in general use to denote the extent of ecclesiastical authority.
Noah Webster's Dictionary
1. (n.) An instrument by means of which the bolt of a lock is shot or drawn; usually, a removable metal instrument fitted to the mechanism of a particular lock and operated by turning in its place.
2. (n.) An instrument which is turned like a key in fastening or adjusting any mechanism; as, a watch key; a bed key, etc.
3. (n.) That part of an instrument or machine which serves as the means of operating it; as, a telegraph key; the keys of a pianoforte, or of a typewriter.
4. (n.) A position or condition which affords entrance, control, pr possession, etc.; as, the key of a line of defense; the key of a country; the key of a political situation. Hence, that which serves to unlock, open, discover, or solve something unknown or difficult; as, the key to a riddle; the key to a problem.
5. (n.) That part of a mechanism which serves to lock up, make fast, or adjust to position.
6. (n.) A piece of wood used as a wedge.
7. (n.) The last board of a floor when laid down.
8. (n.) A keystone.
9. (n.) That part of the plastering which is forced through between the laths and holds the rest in place.
10. (n.) A wedge to unite two or more pieces, or adjust their relative position; a cotter; a forelock.
11. (n.) A bar, pin or wedge, to secure a crank, pulley, coupling, etc., upon a shaft, and prevent relative turning; sometimes holding by friction alone, but more frequently by its resistance to shearing, being usually embedded partly in the shaft and partly in the crank, pulley, etc.
12. (n.) An indehiscent, one-seeded fruit furnished with a wing, as the fruit of the ash and maple; a samara; -- called also key fruit.
13. (n.) A family of tones whose regular members are called diatonic tones, and named key tone (or tonic) or one (or eight), mediant or three, dominant or five, subdominant or four, submediant or six, supertonic or two, and subtonic or seven. Chromatic tones are temporary members of a key, under such names as sharp four, flat seven, etc. Scales and tunes of every variety are made from the tones of a key.
14. (n.) The fundamental tone of a movement to which its modulations are referred, and with which it generally begins and ends; keynote.
15. (n.) Fig: The general pitch or tone of a sentence or utterance.
16. (v. t.) To fasten or secure firmly; to fasten or tighten with keys or wedges.
Int. Standard Bible Encyclopedia
ke (maphteach, an "opener"; compare kleis, "that which shuts"): Made of wood, usually with nails which fitted into corresponding holes in the lock, or rather bolt (Judges 3:25). Same is rendered "opening" in 1 Chronicles 9:27.
Figurative: Used figuratively for power, since the key was sometimes worn on the shoulder as a sign of official authority (Isaiah 22-22). In the New Testament it is used several times thus figuratively: of Peter: "the keys of the kingdom of heaven" (Matthew 16:19); of Christ, in Revelation, having the "keys of death and of Hades" (Revelation 1:18), also having "the key of David" (Revelation 3:7). An angel was given "the key of the pit of the abyss" (Revelation 9:1; Revelation 20:1). our Lord accused the teachers of the law of His day of taking away "the key of knowledge" from men, that is, locking the doors of truth against them (Luke 11:52; compare Matthew 23:13).
Edward Bagby Pollard
Key (8 Occurrences)
Luke 11:52 Woe to you lawyers! For you took away the key of knowledge. You didn't enter in yourselves, and those who were entering in, you hindered." (WEB KJV WEY ASV BBE DBY WBS YLT NAS RSV NIV)
Revelation 3:7 "To the angel of the assembly in Philadelphia write: "He who is holy, he who is true, he who has the key of David, he who opens and no one can shut, and who shuts and no one opens, says these things: (WEB KJV WEY ASV BBE DBY WBS YLT NAS RSV NIV)
Revelation 9:1 The fifth angel sounded, and I saw a star from the sky which had fallen to the earth. The key to the pit of the abyss was given to him. (WEB KJV WEY ASV BBE DBY WBS YLT NAS RSV NIV)
Revelation 20:1 I saw an angel coming down out of heaven, having the key of the abyss and a great chain in his hand. (WEB KJV WEY ASV BBE DBY WBS YLT NAS RSV NIV)
Judges 3:25 They waited until they were ashamed; and behold, he didn't open the doors of the upper room: therefore they took the key, and opened them, and behold, their lord was fallen down dead on the earth. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
1 Chronicles 9:27 They lodged around the house of God, because that duty was on them; and to them pertained its opening morning by morning. (See NIV)
Isaiah 22:22 I will lay the key of the house of David on his shoulder. He will open, and no one will shut. He will shut, and no one will open. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Isaiah 33:6 And she will have no more fear of change, being full of salvation, wisdom, and knowledge: the fear of the Lord is her wealth. (See NIV)