The term 'Summer Sign' refers to the four zodiac signs that are associated with the summer season. These signs are VIRGO (5 letters), PLUS (4 letters), LEO (3 letters), and CANCER (6 letters). VIRGO is a sign of service and humility, PLUS is a sign of ambition and determination, LEO is a sign of courage and leadership, and CANCER is a sign of emotion and intuition. Together, these four signs represent the qualities of the summer season.