Caesario
Could not find Caesarionem in Logeion dictionaries.
Caesarionem Proper-name noun: masculine accusative singular of Caesario
Caesărĭo, ōnis, m., = Καισαρίων,
- son of Caesar by Cleopatra, put to death by the command of Augustus, Suet. Aug. 17; cf. id. Caes. 52.
Cæsărĭō, (16) ōnis, m. , Césarion [fils de César et de Cléopâtre] : Suet. Aug. 17.