The Collaborative International Dictionary of English v.0.48:

Spent \Spent\ (sp[e^]nt), a.
   1. Exhausted; worn out; having lost energy or motive force.
      [1913 Webster]

            Now thou seest me
            Spent, overpowered, despairing of success.
                                                  --Addison.
      [1913 Webster]

            Heaps of spent arrows fall and strew the ground.
                                                  --Dryden.
      [1913 Webster]

   2. (Zool.) Exhausted of spawn or sperm; -- said especially of
      fishes.
      [1913 Webster]

   Spent ball, a ball shot from a firearm, which reaches an
      object without having sufficient force to penetrate it.
      [1913 Webster] Sper