First class and Singular

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

Singular and first class are semantically related. in excellent topic. In some cases you can use "Singular" instead an adjective phrase "First class".

Singular adjective - Being out of the ordinary.

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

Nearby Word: singularity