The Collaborative International Dictionary of English v.0.48:

Phenyl \Phe"nyl\, n. [Gr. fai`nein 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.
   [1913 Webster]

   Phenyl hydrate (Chem.), phenol or carbolic acid.

   Phenyl hydrazine (Chem.), a nitrogenous base
      (C6H5.NH.NH2) produced artificially as a colorless oil
      which unites with acids, ketones, etc., to form easily
      crystallized compounds. It is used in organic chemistry,
      particulary to isolate compounds in pure form for
      analysis.
      [1913 Webster + PJC]