Second-string and Sub-rosa

Second-string adjective - Being a replacement or substitute for a regular member of a team.

Sub-rosa and second-string are semantically related. In some cases you can use "Sub-rosa" instead an adjective phrase "Second-string".

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

Second-string and sub-rosa are semantically related. Sometimes you can use "Second-string" instead an adjective phrase "Sub-rosa".