fret: n. A strip of metal placed vertically across the fretboard of a stringed instrument that marks different pitches of the notes. The higher up the fretboard, the higher the note is musically. v. to press down on the strings of a stringed instrument to play certain notes.

fret marker: A dot on the fretboard of stringed instrument that makes it easier to locate frets. Typically, ukuleles have fret markers on the 5th, 7th, and 10th frets.

fretboard: The strip of wood that runs along the neck of a stringed instrument just behind the strings.

fretted string: A string you play while holding it down at a certain fret.

friction tuner: A mechanism for tuning stringed instruments in which you turn a peg that tightens or loosens the strings and keeps the strings in tune through friction.