To move or hit something with a short sudden movement. (Cambridge Dictionary)
If something flicks in a particular direction, or if someone flicks it, it moves with a short, sudden movement. (Collins Dictionary)
If you flick something away, or off something else, you remove it with a quick movement of your hand or finger. (Collins Dictionary)
If you flick something such as a whip or a towel, or flick something with it, you hold one end of it and move your hand quickly up and then forward, so that the other end moves. (Collins Dictionary)
A sudden quick movement. (Oxford Dictionaries)
The sudden release of a bent finger or thumb, especially to propel a small object. (Oxford Dictionaries)
A light, sharp, quickly retracted blow, especially with a whip. (Oxford Dictionaries)
How to flick a cigarette.
This antiquated technology is why movies are called ”Flicks”.