From Latin 'advenire' (to come to) — literally 'an arrival,' from PIE *gwem- (to come).
The arrival of a notable person, thing, or event; (capitalized) the period before Christmas celebrating the coming of Christ.
From Latin 'adventus' (a coming, an arrival, an approach), a verbal noun from 'advenīre' (to come to, to arrive at, to approach), composed of 'ad-' (to, toward) + 'venīre' (to come). 'Venīre' descends from Proto-Indo-European *gʷem- (to go, to come), reconstructed from its reflexes across multiple branches: Greek 'baínein' (βαίνειν, to go, to step — root of 'base,' 'basis,' and 'acrobat' via 'akrobatein,' to walk on tiptoe), Sanskrit 'gam' (to go — root of 'gamana,' motion, and 'āgama,' arrival), Latin 'venīre' (to come — producing 'venue,' 'adventure' as a coming toward fortune, 'event' as a coming out, 'invent' as a coming upon something, 'prevent' as a coming before), Old English 'cuman' (to come — modern 'come'), Gothic 'qiman,' and Welsh 'dyfod' (to come). The Christian liturgical use of 'Advent' — the four
English 'come' and Latin 'venīre' (to come) are cognates from PIE *gʷem-. The PIE labiovelar *gʷ became 'v' in Latin but 'c/k' in Germanic — which is why 'come' and 'advent' look nothing alike despite sharing an ancestor. 'Adventure' literally means 'about to come' — something that is coming toward you.