Knob
handle protruding from a surface
A knob is a round handle that can be turned or pulled. A doorknob is a round handle that is turned to open a door. A cabinet knob is a small handle that is pulled to open a cabinet door or drawer. A control knob can turn a lamp on and off or make the volume on a radio go up or down.
![](http://up.wiki.x.io/wikipedia/commons/thumb/6/62/Knobs-for-climate-control.jpg/220px-Knobs-for-climate-control.jpg)
A "knob" can also be any small, round thing that sticks out.