neck joint

noun3

1. •
   One of the joints of the neck (it belongs to the vertebral column).
2. •
   One of the joints of the cervical vertebrae (“seven vertebrae of the neck”).
3. •
   Τhe junction where the neck (fretted or unfretted) meets the body of a stringed instrument.

   • On the classical guitar, the heel supports the neck joint on the back side.