The Collaborative International Dictionary of English v.0.48:

Hercules \Her"cu*les\, n.
   1. (Gr. Myth.) A hero, fabled to have been the son of Jupiter
      and Alcmena, and celebrated for great strength, esp. for
      the accomplishment of his twelve great tasks or "labors."
      [1913 Webster]

   2. (Astron.) A constellation in the northern hemisphere, near
      Lyra.
      [1913 Webster]

   Hercules' beetle (Zool.), any species of Dynastes, an
      American genus of very large lamellicorn beetles, esp.
      Dynastes hercules of South America, which grows to a
      length of six inches.

   Hercules powder, an explosive containing nitroglycerin; --
      used for blasting.
      [1913 Webster] Hercules'-club
      Hercules'-club

The Collaborative International Dictionary of English v.0.48:

Dynastidan \Dy*nas"ti*dan\, n. [Gr. ?, fem. of ?. See Dynast.
   The name alludes to the immense size of some species.]
   (Zool.)
   One of a group of gigantic, horned beetles, including
   Dynastus Neptunus, and the Hercules beetle (Dynastus
   Hercules) of tropical America, which grow to be six inches
   in length.
   [1913 Webster]