Though 'turn down' means to refuse, it's often used politely.

Polite Decline

'Turn down' can soften the blow when rejecting offers or proposals.

Gentle Rejection

Use 'turn down' to refuse without emphasizing the negative.

'Turn down' is a common way to ask someone to lower something.

It's often used with devices or systems that have adjustable settings.

Turning down a corner is a quick way to mark pages without a bookmark.

In hospitality, 'turn down service' means preparing the bed for use.