What is the nymphios service in the greek orthodox church.?

"Blessed is that Servant whom He Shall Find Waiting" An Exhortation to Vigilance Sermon on Vigilance by Fr. William Chiganos "Be dressed in readiness," Jesus begins in Luke 12, "and keep your lamps alight" (v. 35), because at any moment, He can step through the door of history and return to us for good. As His bride, will we be eagerly waiting for Him? Will He find a ready home and a tender, welcoming heart? Or will He return to an empty, run-down house, where people grew tired of waiting and moved somewhere else? -- A place where the people He people He loved forgot all about Him? Will He find joy or uneasy surprise? Jesus, of course, would rather find joy. Let's look again at His counsel in verse 35, so we can live in bright anticipation instead of trembling dread:

"Be dressed in readiness, and keep your lamps alight."

Excerpted from Source:

http://www.goarch.org/archdiocese/departments/outreach/resources/sermons/2005/vigilance

On PALM SUNDAY EVENING, as well as on the evenings of Holy Monday, Tuesday, and Wednesday, the faithful gather for the NymphiOS or Bridegroom Services that include readings, hymns, and commemorations that anticipate the Passion of Christ.

Source:

http://www.goarch.org/news/2007-03-21-archbishopexhorts