triodZool.|ˈtraɪɒd| [ad.Gr. τρίοδος a place where three ways meet, f. τρι- tri- + ὁδός way.] Name for a simple triradiate sponge-spicule, consisting of three rays inclined at angles of 120°. 1887Sollas in Encycl.Brit. XXII. 416/2 Fig. 12..c, triod (triaxon triactine).