What is a hypothetical hydrocarbon, C4H4, analogous to benzene; -- so called from the four carbon atoms in the molecule. Tetrol phenol, furfuran. [Obs.] called?

tetrol — A hypothetical hydrocarbon, C4H4, analogous to benzene; -- so called from the four carbon atoms in the molecule. Tetrol phenol, furfuran. [Obs.]. (Webster's 1913.)

Sources