second-class

adjective

1. of the class, rank, excellence, etc. next below the highest; of secondary quality
2. designating or of accommodations next below the best: a second-class railway carriage
3. ☆ designating or of a class of mail consisting of newspapers, periodicals, etc.: such mail carries lower postage rates than first-class mail
4. 1. inferior, inadequate, etc.
   2. lacking or denied full rights, privileges, etc.: a second-class citizen

adverb

1. with accommodations next below the best: to travel second-class
2. as or by second-class mail