| Noun | 1. | Ascension of the Lord - (Christianity) celebration of the Ascension of Christ into heaven; observed on the 40th day after EasterChristian religion, Christianity - a monotheistic system of beliefs and practices based on the Old Testament and the teachings of Jesus as embodied in the New Testament and emphasizing the role of Jesus as savior holy day of obligation - a day when Catholics must attend Mass and refrain from servile work, and Episcopalians must take Communion |