jellyn.[ Formerly gelly, gely, F. gele jelly, frost, fr. geler to freeze. L. gelare; akin to gelu frost. See Gelid.]()1. Anything brought to a gelatinous condition; a viscous, translucent substance in a condition between liquid and solid; a stiffened solution of gelatin, gum, or the like.()2. The juice of fruits or meats boiled with sugar to an elastic consistence; as, currant jelly; calf's-foot jelly.()Jelly bag, a bag through which the material for jelly is strained. -- Jelly mold, a mold for forming jelly in ornamental shapes. -- Jelly plant (Bot.), Australian name of an edible seaweed (Eucheuma speciosum), from which an excellent jelly is made. J. Smith. -- Jelly powder, an explosive, composed of nitroglycerin and collodion cotton; -- so called from its resemblance to calf's-foot jelly.()v. i. To become jelly; to come to the state or consistency of jelly.()