‖ prosodusZool.|ˈprɒsədəs| [mod.L., ad.Gr. πρόσοδος an approach, f. πρός to + ὁδός a way.] An incurrent opening or channel in a sponge. 1887Sollas in Encycl.Brit. XXII. 415/1 (Sponges) The prosopyles..may remain unchanged..or at the most be prolonged into very short tubes, each a prosodus or aditus.