browse words by letter
a b c d e f g h i j k l m n o p q r s t u v w x y z
archaean

more about archaean

archaean


  3  definitions  found 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Archaean  \Ar*ch[ae]"an\,  a.  [Gr.  'archai^os  ancient,  fr  'archh` 
  beginning.] 
  Ancient;  pertaining  to  the  earliest  period  in  geological 
  history. 
 
  From  Webster's  Revised  Unabridged  Dictionary  (1913)  [web1913]: 
 
  Archaean  \Ar*ch[ae]"an\,  n.  (Geol.) 
  The  earliest  period  in  geological  period,  extending  up  to  the 
  Lower  Silurian.  It  includes  an  Azoic  age,  previous  to  the 
  appearance  of  life,  and  an  Eozoic  age,  including  the  earliest 
  forms  of  life. 
 
  Note:  This  is  equivalent  to  the  formerly  accepted  term  Azoic, 
  and  to  the  Eozoic  of  Dawson. 
 
  From  WordNet  r  1.6  [wn]: 
 
  archaean 
  adj  :  (geology)  used  of  the  earliest  known  rocks  [syn:  {archean}] 




more about archaean