I. ˌsecond ˈclass BrE AmE noun [uncountable]
1 . a way of travelling on a ship or train that is cheaper and less comfortable than ↑ first class
2 . a way of delivering letters etc in Britain that is cheaper and slower than ↑ first class
3 . the system in the US for delivering newspapers, magazines, advertisements etc through the post
II. [m2]See main entry: ↑ second-class