There are various synonyms that can be used for the term "single affluent segment". One possible alternative could be "high net worth individual", which refers to someone who has significant financial assets and is capable of making sizable investments. Another option is "upper-class consumer", which suggests a person who belongs to the wealthiest and most privileged social category. "Affluent market" or "luxury consumer group" can also be used to describe individuals or groups of people who have a high level of disposable income and prefer to spend it on high-end products and services. Overall, these terms all suggest a similar type of consumer who is financially successful and able to afford premium products and services.