The term 'Symbol of Simplicity' can be represented by two crossword solutions: PIE and ABC. PIE stands for 'Peace, Integrity, and Equality', which is a slogan that has been used to promote peace and equality since the 1960s. ABC stands for 'A Basic Concept', which is a phrase used to describe something that is simple and easy to understand. Both of these terms are symbols of simplicity, as they represent ideas that are easy to comprehend and promote peace and equality.