Best and Upper-crust

Best adjective - (superlative of `good') having the most positive qualities.

Upper-crust and best are semantically related In some cases you can use "Upper-crust" instead an adjective "Best".

Upper-crust adjective - Of high birth, rank, or station.

Best and upper-crust are semantically related in first-class topic. Sometimes you can use "Best" instead an adjective phrase "Upper-crust".