LATIN DICTIONARYLexicon Latīnum
English → Latin

“imperial” in Latin

The English word imperial itself goes back to Latin in, through imperiālis.

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

imperial
imperatorius: Caesareus (post-Augustan; the times of the emperors; seldom Augustalis and imperialis): often, by genitive: imperatoris, or Caesaris, or Augusti; principalis, or genitive, principis (belonging to the prince or emperor; time of the emperors). His imperial majesty, *majestas imperatoria (as a dignity or title): magnitudo imperatoria (as a title, of the later times of the emperors): your imperial majesty, majestas or magnitudo tua: the imperial territories, *terrae imperatoris.
The imperial title, nomen Augusti or imperatoris (times of emperors): nomen imperatorium (with Cic., ad Fam., 11, 4, 1): appellatio imperatoria (with Velleius, 2, 125, 5; but in both places = title of general). To assume the imperial title (and throne), nomen Augusti arripere.

Quick answer

What is the Latin word for imperial?
The usual Latin words for “imperial” are imperātōrius, Caesareus, imperiālis; also imperātor, Caesar, Augustus. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.