Source : Webster's Revised Unabridged Dictionary (1913)

Spent \Spent\ (sp[e^]nt), a.
   1. Exhausted; worn out; having lost energy or motive force.

            Now thou seest me Spent, overpowered, despairing of
            success.                              --Addison.

            Heaps of spent arrows fall and strew the ground.
                                                  --Dryden.

   2. (Zo["o]l.) Exhausted of spawn or sperm; -- said especially
      of fishes.

   {Spent ball}, a ball shot from a firearm, which reaches an
      object without having sufficient force to penetrate it.