Pronunciation: (yOO'tri-kul), [key]
1. a small sac or baglike body, as an air-filled cavity in a seaweed.
2. Bot.a thin bladderlike pericarp or seed vessel.
3. Anat.the larger of two sacs in the membranous labyrinth of the internal ear. Cf. saccule (def. 1).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.