Concise Bible Dictionary:

The word παρἀδεισος appears to have had an oriental origin. It is said of the king of Persia that he had gardens which were called paradises, full of everything beautiful and good that the earth could produce. The LXX, adopting this word for the garden of Eden, which signifies “delights,” accounts for Eden being often called paradise, and may account for the use of the word in the New Testament as denoting some place of happiness and blessing in the heavens. The Lord on the cross called the place where the thief would be with Him that day Paradise (Luke 23:4343And Jesus said unto him, Verily I say unto thee, To day shalt thou be with me in paradise. (Luke 23:43)). The name is also given to “the third heaven,” to which Paul was caught up (2 Cor. 12:44How that he was caught up into paradise, and heard unspeakable words, which it is not lawful for a man to utter. (2 Corinthians 12:4)); and to the paradise of God, where there is the tree of life (type of Christ), of which the overcomer in the church at Ephesus would have authority to eat (Rev. 2:77He that hath an ear, let him hear what the Spirit saith unto the churches; To him that overcometh will I give to eat of the tree of life, which is in the midst of the paradise of God. (Revelation 2:7)).

Strong’s Dictionary of Greek Words:

of Oriental origin (compare 6508); a park, i.e. (specially), an Eden (place of future happiness, "paradise")
KJV Usage: