pentecost Meaning, Definition & Usage

  1. noun seventh Sunday after Easter; commemorates the emanation of the Holy Spirit to the Apostles; a quarter day in Scotland
    Whitsunday.
  2. noun (Judaism) Jewish holy day celebrated on the sixth of Sivan to celebrate Moses receiving the Ten Commandments
    Shavuot; Shavuoth; Feast of Weeks; Shabuoth; Shavous.

WordNet

Pen"te*cost noun
Etymology
L. pentecoste, Gr. (sc. ) the fiftieth day, Pentecost, fr. fiftieth, fr. fifty, fr. five. See Five, and cf. Pingster.
Definitions
  1. A solemn festival of the Jews; -- so called because celebrated on the fiftieth day (seven weeks) after the second day of the Passover (which fell on the sixteenth of the Jewish month Nisan); -- hence called, also, the Feast of Weeks. At this festival an offering of the first fruits of the harvest was made. By the Jews it was generally regarded as commemorative of the gift of the law on the fiftieth day after the departure from Egypt.
  2. A festival of the Roman Catholic and other churches in commemoration of the descent of the Holy Spirit on the apostles; which occurred on the day of Pentecost; -- called also Whitsunday. Shak.

Webster 1913