Phenyl \Phe"nyl\, n. [Gr. ? to bring to light + -yl: cf. F. ph['e]nyle. So called because it is a by-product of illuminating gas.]

(Chem.) 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.

Source: Webster's Revised Unabridged Dictionary (1913)