1. \Di"a*dem\, n. [F. diad[`e]me, L. diadema, fr. Gr. ?, fr.
   ? to bind round; dia` through, across + ? to bind; cf. Skr.
   d[=a] to bind.]
   1. Originally, an ornamental head band or fillet, worn by
      Eastern monarchs as a badge of royalty; hence (later),
      also, a crown, in general. ``The regal diadem.'' --Milton.
   2. Regal power; sovereignty; empire; -- considered as
      symbolized by the crown.
   3. (Her.) An arch rising from the rim of a crown (rarely also
      of a coronet), and uniting with others over its center.
   {Diadem lemur}. (Zo["o]l.) See {Indri}.
   {Diadem spider} (Zo["o]l.), the garden spider.
   

2. \Di"a*dem\, v. t.
   To adorn with a diadem; to crown.
         Not so, when diadem'd with rays divine.  --Pope.
         To terminate the evil, To diadem the right. --R. H.
                                                  Neale.
   

the tiara of a king (Ezek. 21:26; Isa. 28:5; 62:3); the turban (Job 29:14). In the New Testament a careful distinction is drawn between the diadem as a badge of royalty (Rev. 12:3; 13:1; 19:12) and the crown as a mark of distinction in private life. It is not known what the ancient Jewish "diadem" was. It was the mark of Oriental sovereigns. (See CROWN.)