Source : Webster's Revised Unabridged Dictionary (1913)

Nathless \Nath"less\, adv. [OE. natheles, na the les, not the
   less, AS. n[=a] never. See {Na}, {The}, conj., and cf.
   {Nevertheless}.]
   Nevertheless. [Archaic] --Chaucer. Milton. E. Arnold.