Source : Webster's Revised Unabridged Dictionary (1913)

Resting \Rest"ing\,
   a. & n. from {Rest}, v. t. & i.

   {Resting spore} (Bot.), a spore in certain orders of alg[ae],
      which remains quiescent, retaining its vitality, for long
      periods of time. --C. E. Bessey.