Hilo Keepsake is a Hawaiian-style LEI, which is a traditional necklace made of flowers, leaves, shells, and other natural materials. It is often given as a gift to commemorate special occasions or to show appreciation. The term 'Hilo Keepsake' comes from the city of Hilo, Hawaii, which is known for its beautiful leis. The crossword solution for this term is LEI, which is an acronym for 'long-lasting expression of affection.'