Source : Webster's Revised Unabridged Dictionary (1913)

Enduring \En*dur"ing\, a.
   Lasting; durable; long-suffering; as, an enduring
   disposition. ``A better and enduring substance.'' --Heb. x.
   34. -- {En*dur"ing*ly}, adv. --T. Arnold. --
   {En*dur"ing*ness}, n.

Source : WordNet®

enduringly
     adv : in an enduring manner; "Roman culture was enduringly
           fertilized"