give someone/something the finger
give someone/something the fingerINFORMAL
1. If you give someone or something the finger, you do something which shows your anger at them or lack of respect for them. His business would be more successful if he didn't give the finger to most of the commercial opportunities that come his way. He could afford to give the finger to people like that.
2. If you give someone the finger, you make an offensive gesture with one hand, with the middle finger pointing up and the other fingers bent over. The great thrill was to give passers-by the finger through the window.