Phenyl

Part of speech: noun (n.)

A hydrocarbon radical (C6H5) regarded as the essential residue of benzene, and the basis of an immense number of aromatic derivatives. Phenyl hydrate (Chem.), phenol or carbolic acid. -- Phenyl hydrazine (Chem.), a nitrogenous base (C6H5.N2H3) produced artificially as a colorless oil which unites with acids, ketones, etc., to form well-crystallized compounds.