What is "advene"

Advene \Ad*vene"\, v. i. [L. advenire; ad + venire to come: cf. F. avenir, advenir. See Come.] To accede, or come (to); to be added to something or become a part of it, though not essential. [R.]

Where no act of the will advenes as a coefficient.
--Coleridge.

vb. (context rare English) To accede or to come to; to be superadded to, to be added to something or become a part of it, though inessential.