sempiternal

from WordNet (r) 3.0 (2006)

sempiternal
    adj 1: having no known beginning and presumably no end; "the
           dateless rise and fall of the tides"; "time is endless";
           "sempiternal truth" [syn: {dateless}, {endless},
           {sempiternal}]

from The Collaborative International Dictionary of English v.0.48

Sempiternal \Sem`pi*ter"nal\, a. [L. sempiternus, fr. semper
   always: cf. F. sempiternel.]
   1. Of neverending duration; everlasting; endless; having
      beginning, but no end. --Sir M. Hale.
      [1913 Webster]

   2. Without beginning or end; eternal. --Blackmore.
      [1913 Webster]