Azoic age

from The Collaborative International Dictionary of English v.0.48

Azoic \A*zo"ic\, a. [Gr. 'a priv. + ? life, from ? to live.]
   Destitute of any vestige of organic life, or at least of
   animal life; anterior to the existence of animal life; formed
   when there was no animal life on the globe; as, the azoic.
   rocks.
   [1913 Webster]

   {Azoic age} (Geol.), the age preceding the existence of
      animal life, or anterior to the paleozoic tome. Azoic is
      also used as a noun, age being understood. See
      {Arch[ae]an}, and {Eozoic}.
      [1913 Webster]