The term 'Islands Strings' refers to a type of musical instrument. The two crossword solutions, UKE (3 letters) and UKES (4 letters), are both abbreviations for the same instrument, the ukulele. The ukulele is a small four-stringed instrument that originated in Hawaii and is now popular around the world. It is often used in Hawaiian music, as well as other genres such as jazz, folk, and pop.