High life and Upper class

High life noun - Excessive spending.

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

Upper class noun - The highest class in a society.

High life and upper class are semantically related in wealthy fashionable people topic. You can use "High life" instead a noun phrase "Upper class", if it concerns topics such as cream of society.