i Register
In some senses, imperator is marked as formal. Watch for register when choosing this word.
noun
An emperor.
But to compensate in some degree for what was then taken away, the custom was introduced of bestowing what was termed Triumphalia Ornamenta, that is, permission to receive the titles bestowed upon, and to appear in public with the robes worn by the imperatores of the commonwealth when they triumphed, and to bequeath to their descendants triumphal statues.
Modern emperors and consuls of the year VIII. are no more the imperatores of ancient Rome, and modern religious organizations are but the phantasms of mediæval corporations.
noun
The reigning emperor; Male equivalent of Imperatrix
By a law of the tribunes L. Marius and M. Cato penalties were imposed upon all Imperatores who should be found guilty of having made false returns to the senate, and it was ordained that so soon as they returned to the city they should be required to attest the correctness of such documents upon oath before the city quaestor. […] But to compensate in some degree for what was then taken away, the custom was introduced of bestowing what were Triumphalia Ornamenta, that is, permission to receive the titles bestowed upon and to appear in public with the robes worn by the Imperatores of the commonwealth when they triumphed, and to bequeath to their descendants triumphal statues.
He [w:Trajan] was careful to distinguish and reward merit, and raised men of family, and the kindred of former Imperators, into situations of prominence or command.