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]

WordNet (r) 3.0 (2006):

azoic
    adj 1: before the appearance of life; "azoic rocks contain not
           organic remains"