glycerin jelly(n = noun.substance) - a mixture of glycerin and gelatin that is used in histology for mounting specimens;
is a kind of glyceryl ester

apple jelly, calf's-foot jelly, comb jelly, crabapple jelly, glycerin, grape jelly, jelly, jelly bean, jelly doughnut, jelly egg, jelly fungus, jelly roll morton, mineral jelly, petroleum jelly, royal jelly, sea jelly