Second string and Second-string

Second string noun - A squad of players that are available either individually or as a team to relieve or replace the players who started the game.

Second-string and second string are semantically related. In some cases you can use "Second-string" instead a noun phrase "Second string".

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

Second string and second-string are semantically related. Sometimes you can use "Second string" instead a noun phrase "Second-string".