1. the best, finest, or highest class, grade, or rank.
2. the most expensive and most luxurious class of accommodation on trains, ships, airplanes, etc.
3. (in the U.S. Postal Service) the class of mail consisting of letters, postal cards, or the like, together with all mailable matter sealed against inspection.
4. Brit. Univ. the group receiving the highest distinction in an honors course.
[ 1740-50 ]