4. Turn down
This phrasal verb means to refuse an offer.
The object of this phrasal verb can be the offer itself or the person who has made the offer to us.
Examples:
My supervisor told me they want to give me a promotion, but I think I'm going to turn the new job down. I'm just too busy with my kids to accept more work right now.
Ursula won a free trip to the coast, but she turned it down because her sister is getting married the same weekend.