Run-down and Second-class

Run-down adjective - Showing signs of advanced wear and tear and neglect.

Second-class and run-down are semantically related. In some cases you can use "Second-class" instead an adjective phrase "Run-down".

Second-class adjective - Of little or less value or merit.

Run-down and second-class are semantically related. Sometimes you can use "Run-down" instead an adjective phrase "Second-class".