The crossword solution for the term 'SUMMERTIME, FOR ONE' is ARIA. An ARIA is a type of song or musical composition that is typically found in operas, cantatas, and other forms of vocal music. It is usually sung by a solo voice, with instrumental accompaniment. The term 'ARIA' comes from the Italian word for 'AIR' or 'MELODY'. Summertime is often associated with leisurely activities, such as going to the beach, swimming, and enjoying outdoor activities. Therefore, an ARIA can be seen as a fitting musical representation of summertime, as it is a type of music that is often associated with relaxation and joy.