indulging in every possible luxury; living extravagantly and enjoying luxurious comforts to the fullest
彼は退職してから趣味にお金を使い、贅沢三昧の生活を送っている。
Since retiring he has spent money on his hobbies and is living a life of pure luxury.
旅行中は毎日高級レストランに行き、まさに贅沢三昧だった。
During the trip we went to high-end restaurants every day — it was pure indulgence.
若いうちから贅沢三昧を続けると、あとで困ることが多い。
If you keep living extravagantly while you're young, it often causes problems later.