Old English, from Latin adventus ‘arrival’, from advenire, from ad- ‘to’ + venire ‘come’.
Christians celebrate Advent in their liturgical calendar from Dec 1 - 24, the time of expectant waiting and preparation for the birth of Jesus at Christmas. A second definition of advent is the arrival of faith in the believer or convert. A third is the waiting for the arrival of the Jesus as Messiah, also known as the Second Coming.
For some of us, just getting out of bed in the morning is an adventure.