First class and Loftiest

First class noun - Mail that includes letters and postcards and packages sealed against inspection.

Loftiest and first class are semantically related. in best topic. In some cases you can use "Loftiest" instead an adjective phrase "First class", when it comes to topics like top.

Loftiest adjective - Being at a point or level higher than all others.

First class and loftiest are semantically related. Sometimes you can replace phrase "First class" with "Loftiest", this terms are similar.