Concise Bible Dictionary:

A period of time marked off by that which distinguishes it from other periods, as the Patriarchal age, the Apostolic age. Though these terms do not occur in scripture, many allusions are made to the different ages. Thus we speak of the Antediluvian age, and scripture speaks of the same period as the “old world,” for example, the ordered scene which God did not spare (2 Peter 2:55And spared not the old world, but saved Noah the eighth person, a preacher of righteousness, bringing in the flood upon the world of the ungodly; (2 Peter 2:5)). The “Patriarchal age” embraces the time from the call of Abraham to the release from Egypt and the giving of the law. “From Adam to Moses” excluding both, is an epoch when men’s sins could not be classed as transgressions, seeing there was no definite law such as was given to Adam, or such as was administered by Moses (Rom. 5:13-1413(For until the law sin was in the world: but sin is not imputed when there is no law. 14Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam's transgression, who is the figure of him that was to come. (Romans 5:13‑14)). Again, from Moses to Christ formed a definite period: “the law was given by Moses, but grace and truth came by Jesus Christ” (John 1:1717For the law was given by Moses, but grace and truth came by Jesus Christ. (John 1:17)); “the law and the prophets were until John: since that time the kingdom of God is preached, and every man presseth into it” (Luke 16:1616The law and the prophets were until John: since that time the kingdom of God is preached, and every man presseth into it. (Luke 16:16)). The time when Christ was on earth is in John’s first epistle repeatedly called “the beginning”: the beginning of Christianity, though it is not called an age. We may also distinguish the period of the Church (from the day of Pentecost until the Rapture of the saints), though it is separated from recognized times and seasons. Our Lord not only spoke of the age in which He was on earth, but referred some events to the end or “completion of the age” (Matt. 13:39-40, 4939The enemy that sowed them is the devil; the harvest is the end of the world; and the reapers are the angels. 40As therefore the tares are gathered and burned in the fire; so shall it be in the end of this world. (Matthew 13:39‑40)
49So shall it be at the end of the world: the angels shall come forth, and sever the wicked from among the just, (Matthew 13:49)
). The disciples also asked what would be the sign of that completion (Matt. 24:33And as he sat upon the mount of Olives, the disciples came unto him privately, saying, Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the world? (Matthew 24:3)). Our Lord also spoke of the “coming age,” when His own should receive life eternal (Luke 18:3030Who shall not receive manifold more in this present time, and in the world to come life everlasting. (Luke 18:30); compare also Matt. 12:3232And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come. (Matthew 12:32); Eph. 1:2121Far above all principality, and power, and might, and dominion, and every name that is named, not only in this world, but also in that which is to come: (Ephesians 1:21); Eph. 2:77That in the ages to come he might show the exceeding riches of his grace in his kindness toward us through Christ Jesus. (Ephesians 2:7)). God’s kingdom is a “kingdom of all ages” (Psa. 145:13,13Thy kingdom is an everlasting kingdom, and thy dominion endureth throughout all generations. (Psalm 145:13) margin). Eternity, in reference to the glory of God, to the blessing of the saved, and to the punishment of the wicked, is again and again called the “age of ages,” often translated “forever and ever”: all being consummated in the eternal state. The Greek word is αίών throughout, though often translated “world” in the AV (KJV).

Strong’s Dictionary of Hebrew Words:

from 7867; old age
KJV Usage: