The term 'AUDIO SYSTEMS, FOR SHORT' can be abbreviated to two words: PAS (3 letters) and STEREOS (7 letters). PAS stands for Public Address System, which is a sound system used in public places such as schools, churches, and stadiums. STEREOS stands for Stereophonic Sound System, which is a type of audio system that uses two or more channels to create a realistic sound experience. Both of these systems are commonly used in homes, businesses, and other venues to provide high-quality sound.