Unsaturated 1 : (1) Less concentrated than a saturated solution or vapour. (2) Containing a double or triple bond. An unsaturated molecule can add on other atoms or dicals before saturation is reached (often between two carbon atoms)
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}