The action or fact of coming or being added from outside; extrinsic addition; adventitious occurrence.
Origin
Late 15th century; earliest use found in Apology for Lollard Doctrines. From post-classical Latin advention-, adventio removal or transfer of relics, appearance (of a suitor in court), acquisition, something acquired, approach, coming from classical Latin advent-, past participial stem of advenīre to come (to) + -iō.