The term 'Guitar LINE' can be broken down into two words, 'Guitar' and 'LINE'. The word 'Guitar' refers to a stringed musical instrument that is usually played with the fingers or a pick. The word 'LINE' refers to a single string of a guitar, which is typically made up of metal frets. The crossword solution for this term is 'FRET', which is a small raised bar on the neck of a guitar that divides the strings into different notes. Fretting a guitar allows the musician to play different notes and chords.