Nitrobenzene \Ni`tro*ben"zene\ (? or ?), n. [Nitro- + benzene.] (Chem.) A yellow aromatic liquid ({C6H5.NO2}), produced by the action of nitric acid on benzene, and called from its odor {imitation oil of bitter almonds}, or {essence of mirbane}. It is used in perfumery, and is manufactured in large quantities in the preparation of aniline. Fornerly called also {nitrobenzol}.