(New Testament) the rising of the body of Jesus into heaven on the 40th day after his Resurrection WordNet 3.0 & Open English WordNet

The Ascension of Jesus is the Christian belief, reflected in the major Christian creeds and confessional statements, that Jesus ascended to Heaven after his resurrection, where he was exalted as Lord and Christ, sitting at the right hand of God. Wikipedia

In Christianity, the departure of the risen Christ from Earth into the presence of God, said to have taken place 40 days after the resurrection, as described in Acts 1 Wikidata

The rising of the body of Jesus into heaven on the 40th day after his Resurrection. OmegaWiki