C6H5

from 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]