Utricle
Utricle , noun
[Latin utriculus a little womb, a calycle, dim. of uter, utris, a bag or bottle made of an animal's hide: compare French utricule.]
1.
A little sac or vesicle, as the air cell of fucus, or seaweed.
2.
(Physiology) A microscopic cell in the structure of an egg, animal, or plant.
3.
(Botany) A small, thin-walled, one-seeded fruit, as of goosefoot. — Gray
4.
(Anatomy) A utriculus.