Verses with the word eighth in the New Testament (6 verses):

Luke 1:59
And it came to pass, that on the eighth day they came to circumcise the child; and they called him Zacharias, after the name of his father.

Acts 7:8
And he gave him the covenant of circumcision: and so Abraham begat Isaac, and circumcised him the eighth day; and Isaac begat Jacob; and Jacob begat the twelve patriarchs.

Philippians 3:5
Circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, an Hebrew of the Hebrews; as touching the law, a Pharisee;

2 Peter 2:5
And 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;

Revelation 17:11
And the beast that was, and is not, even he is the eighth, and is of the seven, and goeth into perdition.

Revelation 21:20
The fifth, sardonyx; the sixth, sardius; the seventh, chrysolyte; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst.