What does advent mean?
The definition of advent
Ad`vent, n.
Etym: [L. adventus, fr. advenire, adventum: cf. F. avent. See Advene.]

1 (Eccl.)
The period including the four Sundays before Christmas. Advent Sunday (Eccl.), the first Sunday in the season of Advent, being always the nearest Sunday to the feast of St. Andrew (Now. 30). Shipley.
2 The first or the expected second coming of Christ.
3 Coming; any important arrival; approach. Death’s dreadful advent. Young. Expecting still his advent home. Tennyson.