るすばん留守番rusuban
1.

The act of remaining in a home or property to ensure its safety and security while the primary occupants are away.

2.

The responsibility assumed by an individual to oversee and protect a household in the absence of its owners.

3.

A role involving the monitoring of a residence, often entrusted to someone while the inhabitants are outside for an extended period.

Example:

その子は留守番をしなければならないと言って怒っていた。

るすばんでんわ留守番電話rusubandenwa
1.

A device that automatically answers incoming calls and records messages when the owner is unavailable to take the call.

2.

A system designed to capture and store voice messages left by callers during the periods when the recipient is not present to respond.

3.

An automated telephone feature that provides a means for callers to communicate their messages when the intended recipient is out of reach.

4.

A telephone service that manages calls in the absence of the user by responding to callers and saving their audio messages for later retrieval.

Example:

あなたは留守番電話を買うべきだ。