First class and Incorrupt

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

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

Incorrupt adjective - Free of corruption or immorality.

First class and incorrupt are semantically related. Sometimes you can use "First class" instead an adjective "Incorrupt".