Doryphoroi in Rome

[Kai]

Pretty sure it means the Praetorians. It is a quite usual Greek word for bodyguard. Cassius Dio e.g. also describes them as being doryphoroi:

Καὶ παραυτίκα γε τοῖς δορυφορήσουσιν αὐτὸν διπλάσιον τὸν μισθὸν τοῦ τοῖς ἄλλοις στρατιώταις διδομένου ψηφισθῆναι διεπράξατο, ὅπως ἀκριβῆ τὴν φρουρὰν ἔχῃ. (53,11)

But of course, the word can also be used quite generic and could mean any kind of guard then...