Source : Webster's Revised Unabridged Dictionary (1913)

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.

   2. Without beginning or end; eternal. --Blackmore.

Source : WordNet®

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