In crowds and Upper crust

Upper crust and in crowds are semantically related. in high society topic. In some cases you can use "Upper crust" instead a noun phrase "In crowds", when it comes to topics like high-class persons, wealthy fashionable people.

Upper crust noun - Individuals carefully selected as being the best of a class.

In crowds and upper crust are semantically related. Sometimes you can replace phrase "In crowds" with "Upper crust", this phrases are similar.