Obscene finger gesture

An obscene finger gesture is a unique hand movement used when one wishes to express hate, anger or overall discord with another individual. It has also been referred to as flipping the bird, or giving one the middle finger. It is executed by closing the hand into a fist and positioning it vertically with the knuckles facing the intended target and the middle finger extended outward. It is considered a vulgar gesture and is not one that is used in polite company.

Examples
In the 1986 film Star Trek IV: The Voyage Home, Admiral James T. Kirk, in present-day Earth, asks a punker on a bus to turn down his loud radiol. The punker replies by extending Kirk the middle finger right at a point where the crooner on the radio shouts the words, "Screw you!" very loudly. Kirk's comrade, Captain Spock responded with a unique hand gesture of his own, the Vulcan nerve pinch, which rendered the punker unconscious. His head slammed down on his radio, inadvertently shutting it off.