Ill-mannered and Second-class

Ill-mannered adjective - Showing a lack of manners or consideration for others.

Second-class and ill-mannered are semantically related. In some cases you can use "Second-class" instead an adjective phrase "Ill-mannered".

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

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