Im·pe·ri·al a.
 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.”
 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. Zool. 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.