The term 'Blue Flag' can be represented by two crossword solutions, IRIS and IRID. IRIS is a genus of flowering plants with showy flowers that come in a variety of colors, including blue. The word IRID is derived from the Greek word for rainbow, and it is also used to refer to a group of plants that includes the IRIS genus. Both words are commonly used to describe the blue flag, a symbol of peace, neutrality, and truce.