First class and Topmost

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

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

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

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

Nearby Word: top