Furfuran \Fur"fu*ran\, n. [L. furfur bran.] (Chem.) A colorless, oily substance, {C4H4O}, obtained by distilling certain organic substances, as pine wood, salts of pyromucic acid, etc.; -- called also {tetraphenol}. Glycolide \Gly"co*lide\, n. [Glycol + anhydride.] (Chem.) A white amorphous powder, {C4H4O}, obtained by heating and dehydrating glycolic acid. [Written also {glycollide}.]