stylus

‖n. [ L. stylus, or better stilus. ] 1. An instrument for writing. See Style, n., 1. [ 1913 Webster ]

2. That needle-shaped part at the tip of the playing arm of phonograph which sits in the groove of a phonograph record while it is turning, to detect the undulations in the phonograph groove and convert them into vibrations which are transmitted to a system (since 1920 electronic) which converts the signal into sound; also called needle. The stylus is frequently composed of a hard metal or of diamond. [ PJC ]

3. The needle-like device used to cut the grooves which record the sound on the original disc during recording of a phonograph record; it is moved by the vibrations given to the diaphragm by a sound, and produces the indented record. [ PJC ]

4. (Computers) A pen-shaped pointing device used to specify the cursor position on a graphics tablet. [ PJC ]