noun
former owner (of a collection)
Used in contexts such as libraries, museums, or art collections to refer to the previous owner of an item or collection.
この古書には旧蔵者の蔵書印が押してある。
This old book bears the ownership seal of its former owner.
展示品の旧蔵者は有名な美術収集家だった。
The former owner of the exhibited items was a famous art collector.