- noun a rounded part that controls something
- noun a round button (such as on a monitor), which can be turned to control some process
- A usually round or somewhat spherical handle by which a latch, lock, or other device is operated.
- Any similarly shaped ornament.
- A protuberance, such as a rounded piece of plastic, which serves to adjust, control, actuate, tighten, or loosen. A knob may, for instance, have a pointer incorporated, to set a desired value within a graduated scale, as seen in a rotary switch.
- noun the penis. The word has been in use with this sense since the 19th century and was the most common vulgar synonym in Britain and Australia in the 1950s and 1960s, since when such words as dick and prick have increased in popularity.
- verb to have sex (with). This is a variant of nob, and is said by users of the word to be the incorrect spelling, in spite of the derivation.