Pronunciation: (hī"pu-ton'ik), [key]
1. Physiol.(of tissue) having less than the normal tone.
2. Physical Chem.noting a solution of lower osmotic pressure than another solution with which it is compared (opposed to hypertonic). Cf. isotonic (def. 1).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.