noun
owning many clothes; person with a large wardrobe
Can refer to the state of having many clothes or to a person who owns a lot of clothes. Often used in a slightly admiring or envious tone.
彼女は本当に衣装持ちで、毎日違う服を着ている。
She really has a lot of clothes and wears something different every day.
うちの母は衣装持ちだから、クローゼットがいつもいっぱいだ。
My mother owns a ton of clothes, so her closet is always full.
おしゃれ describes someone who is stylish or fashion-conscious, while 衣装持ち specifically emphasizes the quantity of clothes owned.
Compound of 衣装 (clothing) and 持ち (holding, owning). The exact historical derivation is uncertain, but the meaning is transparent from its components.