forefinger
The finger next to your thumb that you usually point with.
The forefinger is the finger next to your thumb, the one you naturally point with when showing someone a direction or calling attention to something. It's also called the index finger because people use it to point at items in lists or indexes.
Your forefinger is usually your strongest and most precise finger after your thumb. When you press a doorbell, use a game controller, or tap a key while typing, you're probably using your forefinger. Violinists and guitarists rely heavily on their forefingers to hold down strings accurately.
In some cultures, pointing with your forefinger at people is considered rude, though pointing at objects or directions is usually fine. Your forefinger works closely with your thumb for precise tasks: together they can pick up a grain of rice, thread a needle, or turn a tiny screw.