noun
General noun for holding or keeping something in custody or in a place; often used in legal or administrative contexts.
容疑者は警察署に留め置きされた。
The suspect was detained at the police station.
書類は受付に留め置きになっている。
The documents are being held at the reception desk.
noun
mail held at the post office
Abbreviation of 郵便局留め置き; refers to mail held for pickup at a post office instead of being delivered.
この荷物は留め置きでお願いします。
Please hold this package at the post office for pickup.
Compound of 留め (tome, 'stopping') + 置き (oki, 'placing'). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning of holding or keeping something in place.