Pronunciation: (un-sach'u-rā"tid), [key]
1. not saturated; having the power to dissolve still more of a substance.
2. Chem.(of an organic compound) having a double or triple bond and capable of taking on elements or groups by direct chemical combination without the liberation of other elements or compounds, as ethylene, CH2=CH2; undersaturated.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.