Noun | 1. | isotonic solution - a solution having the same osmotic pressure as blood solution - a homogeneous mixture of two or more substances; frequently (but not necessarily) a liquid solution; "he used a solution of peroxide and water" Ringer solution, Ringer's solution - an aqueous solution containing the chlorides of sodium and potassium and calcium that is isotonic to animal tissues; used to correct dehydration and (in physiological experiments) as a medium for in vitro preparations saline, saline solution - an isotonic solution of sodium chloride and distilled water |