(1) A condition or property of a solution in which it has less amount of solutes than that of another solution with which it is compared.
(2) A condition or property of a solution which has lower tonicity as the other solution with which it is compared.
(3) A condition in which there is a lesser degree of tone or tension.
Hypotonicity occurs when the extracellular fluid has lower amount of solutes than in the cytoplasm. In this condition, the water molecules move into the cell.
Related forms: hypotonic (adjective)
Compare: hypertonicity, isotonicity
See also: tonicity