The phrase "more sub rosa" refers to something that is being kept secret or confidential. Its antonyms include words like overt, public, open, and transparent. When something is overt, it is not being hidden or kept a secret but is out in the open for all to see. Similarly, when something is public, it is intended to be known by everyone. The opposite of sub rosa can also be expressed as open, which implies a lack of secrecy or concealment. When something is transparent, it is clear and understandable, leaving no room for hidden or obscure meanings. Hence, these antonyms signify the opposite of what "more sub rosa" implies.