knob
UK[nɒb]US[nɑːb]
n
a round handle on a door, drawer, or piece of equipment, that you use to open it
n
a round lump on the surface or end of something
n
a round switch on a piece of equipment that you turn to adjust it
Etymology
the word "knob" entered middle english from middle low german "knobbe," meaning a knot or rounded protuberance. it is related to other germanic words for lump or knot, such as old english "cnotta" (the source of modern "knot") and middle dutch "cnobbe." the core semantic concept across these related terms is that of a small, rounded mass or swelling. this shared root meaning evolved naturally into the modern senses of a rounded handle, a lump on a surface, or a control switch, all of which retain the fundamental idea of a small, rounded object.
Analysis
this word is a tight germanic root and cannot be meaningfully segmented into smaller morphemes based on its modern english spelling.
Examples
she turned the brass knob and opened the heavy door.
a bony knob protruded from his wrist.
adjust the volume using the knob on the amplifier.