Carat and World-class

Carat noun - The unit of measurement for the proportion of gold in an alloy; 18-karat gold is 75% gold; 24-karat gold is pure gold.

World-class and carat are semantically related. In some cases you can use "World-class" instead an adjective "Carat".

World-class adjective - Ranking above all others.

Carat and world-class are semantically related. Sometimes you can use "Carat" instead an adjective phrase "World-class".