Second-string and Second banana

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

Second banana and second-string are semantically related. In some cases you can replace phrase "Second banana" with "Second-string", this phrases are similar.

Second banana noun - Someone who serves in a subordinate capacity or plays a secondary role.

Second-string and second banana are semantically related. Sometimes you can use "Second-string" instead an adjective phrase "Second banana".