nObventionThe act of happening incidentally; that which happens casually; an incidental advantage; an occasional offering."Tithes and other obventions .""Legacies bequeathed by the deaths of princes and great persons, and other casualities and obventions ."
Century Dictionary and Cyclopedia
nobventionThat which happens or is done or made incidentally or occasionally; incidental advantage; specifically, an offering, a tithe, or an oblation.
Chambers's Twentieth Century Dictionary
nObventionob-ven′shun (obs.) any incidental occurrence, or advantage, esp. an offering.
Webster's Revised Unabridged Dictionary
L. obvention, fr. obvenire, to come before or in the way of, to befall; ob,see Ob-) + venire, to come: cf. F. obvention,