What is Advowson Collative?

Legal Definition
Where the bishop happens himself to be the patron, in which case (presentation being impossible, or unnecessary) he does by one act, which is termed "collation," or conferring the benefice, all that is usually done by the separate acts of presentation and institution. 2 Bl. Comm. 22, 23; 1 Crabb, Real Prop. p. 13i, ยง 119.
-- Black's Law Dictionary
Legal Definition
An advowson wherein the patron is the bishop.
-- Ballentine's Law Dictionary