| ̷ ̷ ̷ ̷+ noun
Etymology: International Scientific Vocabulary quater- + phenyl
: any of several crystalline aromatic hydrocarbons C 6 H 5 (C 6 H 4 ) 2 C 6 H 5 that contain a sequence of four benzene rings in the molecule ; especially : the isomer whose central rings are attached at para positions and which is made by pyrolysis of biphenyl