turn down

verb3

1. •
   To reposition by turning, flipping, etc. in a downward direction; to double or fold down.

   • Turn down the blankets to let them air out.
2. •
   To refuse, decline, or deny.

   • He turned down all our offers of help.
3. •
   To reduce the power, etc. of something by means of a control, such as the volume, heat, or light.

   • Turn down the television so I can hear myself think.
   • When it starts to boil, turn down the heat to a simmer.