The Collaborative International Dictionary of English v.0.48:

Termless \Term"less\, a.
   1. Having no term or end; unlimited; boundless; unending; as,
      termless time. [R.] "Termless joys." --Sir W. Raleigh.
      [1913 Webster]

   2. Inexpressible; indescribable. [R.] --Shak.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "termless":
   all-comprehensive, all-inclusive, boundless, countless, endless,
   eternal, exhaustless, extending everywhere, illimitable, illimited,
   immeasurable, immense, incalculable, incomprehensible,
   inexhaustible, infinite, infinitely continuous, innumerable,
   interminable, interminate, limitless, measureless, no end of,
   perpetual, shoreless, sumless, unbounded, uncircumscribed,
   unfathomable, universal, unlimited, unmeasurable, unmeasured,
   unnumbered, unplumbed, untold, without bound, without end,
   without limit, without measure, without number