STRUM' (4 letters) The term 'UKE RIDGE' is composed of two crossword solutions, 'FRET' and 'STRUM'. FRET is a four-letter word meaning to feel or show anxiety or concern, while STRUM is a four-letter word meaning to play a stringed instrument with a sweeping motion of the fingers. Together, these two words form the term 'UKE RIDGE', which refers to the raised edge of a ukulele's fretboard, which is used to help the player STRUM the strings.