Translation of "sub rosa" into English

"In secret", "privately", "confidentially" or "covertly". In the Middle Ages, a rose was suspended from the ceiling of a council chamber to indicate that what was said in the "under the rose" was not to be repeated outside. This practice originates in Greek mythology, where Aphrodite gave a rose to her son Eros, and he, in turn, gave it to Harpocrates, the god of silence, to ensure that his mother's indiscretions—or those of the gods in general, in other accounts—were kept under wraps.