Source : Webster's Revised Unabridged Dictionary (1913)

Imperial \Im*pe"ri*al\, a. [OE. emperial, OF. emperial, F.
   imp['e]rial, fr. L. imperialis, fr. imperium command,
   sovereignty, empire. See {Empire}.]
   1. Of or pertaining to an empire, or to an emperor; as, an
      imperial government; imperial authority or edict.

            The last That wore the imperial diadem of Rome.
                                                  --Shak.

   2. Belonging to, or suitable to, supreme authority, or one
      who wields it; royal; sovereign; supreme. ``The imperial
      democracy of Athens.'' --Mitford.

            Who, as Ulysses says, opinion crowns With an
            imperial voice.                       --Shak.

            To tame the proud, the fetter'd slave to free, These
            are imperial arts, and worthy thee.   --Dryden.

            He sounds his imperial clarion along the whole line
            of battle.                            --E. Everett.

   3. Of superior or unusual size or excellence; as, imperial
      paper; imperial tea, etc.

   {Imperial bushel}, {gallon}, etc. See {Bushel}, {Gallon},
      etc.

   {Imperial chamber}, the, the sovereign court of the old
      German empire.

   {Imperial city}, under the first German empire, a city having
      no head but the emperor.

   {Imperial diet}, an assembly of all the states of the German
      empire.

   {Imperial drill}. (Manuf.) See under 8th {Drill}.

   {Imperial eagle}. (Zo["o]l.) See {Eagle}.

   {Imperial green}. See {Paris green}, under {Green}.

   {Imperial guard}, the royal guard instituted by Napoleon I.
      

   {Imperial weights and measures}, the standards legalized by
      the British Parliament.