Sub-rosa and Undercover

Sub-rosa adjective - Designed and carried out secretly or confidentially.

Undercover and sub-rosa are semantically related in secret topic. In some cases you can use "Undercover" instead an adjective phrase "Sub-rosa", when it comes to topics like sneaky, deceitful, underhand, stealthy.

Undercover adjective - Undertaken or done so as to escape being observed or known by others.

Sub-rosa and undercover are semantically related in secret topic. You can use "Sub-rosa" instead an adjective "Undercover".