Verses with the word pentecost in the New Testament (3 verses):

Acts 2:1
And when the day of Pentecost was fully come, they were all with one accord in one place.

Acts 20:16
For Paul had determined to sail by Ephesus, because he would not spend the time in Asia: for he hasted, if it were possible for him, to be at Jerusalem the day of Pentecost.

1 Corinthians 16:8
But I will tarry at Ephesus until Pentecost.