From Longman Dictionary of Contemporary Englishgive somebody the fingergive somebody the fingerAmerican English informal to show someone you are angry with them in a very offensive way by holding up your middle finger with the back of your hand facing them → finger
Examples from the Corpus
give somebody the finger• As the vans move right over to pass them one of the men gives the team the finger.• People, young, old and indifferent, can have purple hair, swear at ballgames or give other motorists the finger.• The Master of Dreams was giving me the finger. 