The term sub rosa is Latin for “under the rose,” The term carries a connotation of secrecy and confidentiality. Something which is said sub rosa should not repeated or widely disseminated, and it could be considered “off the record.” The link between being under the rose and confidentiality goes back to ancient times.
In Egypt, roses were linked with the god Horus, who was associated with silence by the Greeks and Romans due to an unfortunate mistranslation of a hieroglyphic representation of Horus. As a result, the Greeks and Romans began using the rose as a symbol for silence, with secret meetings literally being held under a rose to remind the people present that they were expected to remain silent about the events of the meeting.
The Romans also painted roses on the roofs of their banquet halls, as a reminder to guests that they should remain silent about the events of banquets, and that comments said “sub vino,” under the influence of wine, should not be repeated. Spreading information said during a sub rosa event or conversation would have been viewed as an extremely unwise move politically and socially, if the gossiper was caught.
The tradition of depicting roses on spaces meant for privacy and silence endures. Many confessionals, for example, have rose motifs to remind those in the confessional that the conversation is sub rosa, and rose motifs can be seen in some private rooms in halls of legislature as well.
In the Medieval era, the concept of a sub rosa meeting or conversation endured, and roses were hung in private chambers and meeting halls to remind those present that privacy was essential. Generally, the fact that the conversation was sub rosa would not have been spelled out, as people were expected to know that sitting under a rose represented a contractual obligation for silence.
In modern times, people may specify that a conversation is “sub rosa” to ensure that those involved understand that it is meant to be private, and the term is also used as a euphemism for covert operations.