From finger +‎ board.

fingerboard (plural fingerboards)

1. (music, lutherie) A flat or roughly flat strip on the neck of a stringed instrument, against which the strings are pressed to shorten the vibrating length and produce notes of higher pitches.
2. A miniature skateboard or snowboard that is propelled by the fingers.
3. Synonym of hangboard (“device for building finger strength”).

• The Oxford English Dictionary

• board finger