fingerboard

As a noun fingerboard

is (music) 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.

As an adjective false is

(label) one of two states of a boolean variable; logic.

As a noun fingerboard

is (music) 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.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between fingerboard and keyboard

is that fingerboard is (music) 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 while keyboard is keyboard (electronic musical instrument with keys of a musical keyboard).