资料来源 : Webster's Revised Unabridged Dictionary (1913)

Dracontic \Dra*con"tic\, a. [From L. draco dragon, in allusion
   to the terms dragon's head and dragon's tail.] (Astron.)
   Belonging to that space of time in which the moon performs
   one revolution, from ascending node to ascending node. See
   {Dragon's head}, under {Dragon}. [Obs.] ``Dracontic month.''
   --Crabb.