noun
extravagant person; luxury lover
Rare term for someone who habitually lives in luxury or spends lavishly. Often carries a slightly critical or envious tone.
彼は若い頃からぜいたく屋で、高級車を何台も乗り回していた。
He's been a luxury lover since he was young, driving around in several high-end cars.
贅沢者 is a more common and neutral word for a person who enjoys luxury. 贅沢屋 is rarer and can sound more colloquial or judgmental.
Compound of 贅沢 (zeitaku, 'luxury, extravagance') and 屋 (ya, suffix for a person with a certain trait or occupation). The exact origin is uncertain, but it follows a common pattern for labeling a person by their characteristic.