Low and Second-string

Low adjective - Being near the equator.

Second-string and low are semantically related In some cases you can use "Second-string" instead an adjective "Low".

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

Low and second-string are semantically related in insignificant topic. Sometimes you can use "Low" instead an adjective phrase "Second-string", if it concerns topics such as inferior, minor, lesser, under.