The term 'WAS IN SESSION' can be solved by the three letter word 'SAT'. SAT stands for Scholastic Aptitude Test, which is a standardized test used by colleges and universities in the United States to assess the academic readiness of applicants. The SAT is typically taken by high school students as part of the college admissions process. The test is administered several times a year and is usually taken in the spring of the student's junior year. The SAT is composed of multiple-choice questions and an essay section, and is designed to measure a student's knowledge and skills in reading, writing, and mathematics.