Quiz: Remember the definition of mal de mer?
c.1300, "ascent of Christ into Heaven on the 40th day after the Resurrection," from Latin ascensionem (nominative ascensio) "a rising," noun of action from past participle stem of ascendere "to mount, ascend, go up" (see ascend). Astronomical sense is recorded late 14c.; meaning "action of ascending" is from 1590s. Related: Ascensional.