( NAmE , informal ) to raise your middle finger in the air with the back part of your hand facing sb, done to be rude to sb or to show them that you are angry
GIVE SB THE FINGER
Meaning of GIVE SB THE FINGER in English
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005