fretboard
The long area of the guitar under the strings where the player applies pressure with his or her non-strumming in order to produce different notes; the long, flat area on the front of a guitar neck
Wow, that guitar player is fast! His fingers were really flying up and down the fretboard.
Ivory Fretboard
You go anal on your parter while air guitaring the solo to Stairway to Heaven on your penis.
I hooked up with Jessica last night, we put on a Led Zeppelin CD and I totally Ivory Fretboarded her.