the 40th day after Easter, when the Ascension of Christ into heaven is celebrated
Ascension Day in American English
the fortieth day after Easter, celebrating the Ascension
Ascension Day in American English
noun
the 40th day after Easter, commemorating the Ascension of Christ; Holy Thursday
Word origin
[1325–75; ME]This word is first recorded in the period 1325–75. Other words that entered Englishat around the same time include: division, glaze, pattern, position, wave