Give somebody the finger
Definition 1 of 1
Pro Tip 1/3Very Rude
This gesture is considered highly offensive and should be used with extreme caution, if at all. 
Giving someone the finger usually creates hostility or confrontation.
Pro Tip 2/3Nonverbal Insult
It's a silent way to show anger or disapproval without using words. 
When the driver cut her off, she gave him the finger instead of shouting.
Pro Tip 3/3Cultural Variance
Understanding varies globally; what's offensive in one place might not be in another. 
When he gave the finger in America, it was offensive, but not in his home country.