turn somebody/something ↔ down phrasal verb ( see also ↑ turn )
1 . to turn the switch on a machine such as an ↑ oven , radio etc so that it produces less heat, sound etc OPP turn up :
Can you turn the TV down? I’m trying to work.
2 . to refuse an offer, request, or invitation:
They offered her the job but she turned it down.
I’m not going to turn down an invitation to go to New York!
Josie’s already turned him down (=refused his offer of marriage) .