nib
The pointed metal tip of a pen that writes ink.
A nib is the pointed metal tip of a fountain pen or dip pen where the ink flows out onto paper. The nib usually has a small slit down the middle that helps control how the ink transfers from the pen to the page. When you write with a fountain pen, you're really writing with the nib.
Before ballpoint pens became common in the 1950s, most people wrote with pens that had nibs. Different nibs produced different styles of writing: some were flexible and created thick and thin lines depending on pressure, while others made consistent, fine lines. Calligraphers today still use special nibs to create beautiful lettering, and many writers prefer fountain pens because the nib glides smoothly across paper.
The word can also refer to any pointed or projecting tip, like the pointed end of a tool. If you've ever used a pencil down to a tiny stub, that little point you're holding is sometimes called a nib, too.