Middle finger( means f* off)

It’s an offensive gesture
Offensive: very rude and disrespectful
gesture: a body movement，motion. Like I wave to you or I blow you a kiss

To give someone a middle finger

也可以说：
Flipping the bird 🖕 （bird指中指，布吉岛为什么）
（to flip something means to turn it over very quickly ）
I flipped him the bird because he cut me off.

when guys do catcalls，girls can flipped the bird to them.