Definitions for "Contractile vacuole"
An organelle often found in protozoa that pumps excess water out of the cell to keep the cell from bursting in a hypotonic environment (like freshwater).
In appearance, round and clear; functions in water regulation in freshwater protists.
a spherical drop of watery fluid which makes its appearance periodically at some particular spot near the surface of the animals body, or, if more than one such vacuole is present, at several definite and constant places