All 3 Uses

advent
in
A Prayer for Owen Meany
(Edited)

The first rehearsal, in the nave of the church, was held on the Second Sunday of Advent and followed a celebration of the Holy Eucharist.
p. 163.3

Advent = Christianity: the period that includes the four Sundays preceding Christmas (in remembrance of the birth of Jesus)
...the women wished to say that the Quiet Day they had scheduled for the beginning of Advent had been very successful—that the meditations, and the following period of quiet, for reflection, had been well received.
p. 163.4 *
But that Second Sunday of Advent, in the nave of Christ Church, I felt angry with Owen—once the hairs on the back of my neck relaxed.
p. 164.4

Definitions:

(1) (advent as in: the advent of)
an arrival or beginning -- especially of something important or significant
(2) (Advent as in: the first Sunday of Advent)
a Christian season that includes the four Sundays preceding Christmas (to celebrate the birth of Jesus)
(3) (meaning too rare to warrant focus)
Less commonly, Advent can be the name of a place.