TO TURN DOWN
To decrease the temperature, volume, etc.
Example: Alice was unable to turn down the heat in her apartment.
TO TURN DOWN
To reject
Example: Steventurned downthe acting job because he doesn't want to move to LA.
Why is it so hot in here?
The heating is broken. I can't turn it down!
We would love to offer you the lead role in our latest movie. We start recording in 3 months in Los Angeles.
That's a very kind offer, but I'm going to have to turn you down. I don't want to move to the west coast.