WordNet sense 1 ((Christianity) celebration of the Ascension of Christ into heaven; observed on the 40th day after Easter):

Ascension Day, Ascension of the Lord

WordNet sense 2 (a movement upward):

ascent, rise, rising

WordNet sense 3 ((New Testament) the rising of the body of Jesus into heaven on the 40th day after his Resurrection):

Ascension of Christ

WordNet sense 4 (the act of changing location in an upward direction):

ascending