The term 'Opera Girl' can be summed up by the crossword solution AIDA, which is a four-letter word. AIDA is an opera composed by Giuseppe Verdi in 1871. It is based on a story of an Ethiopian princess who is captured and enslaved in Egypt. The main character, AIDA, is a strong female lead who is torn between her love for an Egyptian captain and her loyalty to her homeland. The opera has been performed around the world and is considered one of the most popular operas of all time.