The antonym of under-privileged is privileged. Privileged refers to those who have special rights, advantages, or opportunities. They are the ones who have access to resources and facilities easily. From housing and education to healthcare and basic facilities, they get what they want without any difficulties. Being privileged is a state of advantage that some people are born with, while others strive hard to attain it. Additionally, Privileged people tend to be more fortunate and have a higher socio-economic status compared to those who are under-privileged. In summary, the antonym of under-privileged is privileged- a state of advantage that many aspire to achieve.