adventition
/ˌadv(ə)nˈtɪʃn/ /ˌadvɛnˈtɪʃn/Now rare
noun
The action or fact of occurring adventitiously; extrinsic addition or influence; accidental or incidental occurrence.
Origin
Mid 17th century; earliest use found in Owen Felltham (?1602–1668), essayist and poet. Probably alteration of advention after adventitious.