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