The two crossword solutions for the term FRAT CHARACTERS are PSIS (4 letters) and MUS (3 letters). PSIS stands for 'Pledges, Sisters, Initiates, and Sisters' and is a term used to refer to the members of a fraternity or sorority. MUS stands for 'Members of the United Sorority' and is a term used to refer to the members of a sorority. Both terms are used to refer to the members of a fraternity or sorority, which are organizations that promote social interaction and academic achievement among college students.