the act of agreeing to something
A settlement was finally reached following Prendi's accession to Romantik's demands.
when someone takes possession of a right or takes on a position of authority, especially some high office such as that of a political leader
The Stuarts were restored in 1660 with the accession of Charles II.
a property owner's right to everything that is added to the property, either naturally or through improvements (eg further building work)
It is through accession that property in minerals belongs to the rightful title holder.