midterm examination
Used in educational contexts for a formal exam held midway through a term.
I have midterm exams next week, so I'm studying at the library every day this week.
期末考査 is the final examination at the end of a term, while 中間考査 is the midterm examination.
中間試験 is a more common synonym for 'midterm exam'; 中間考査 is slightly more formal and often used in official school contexts.
Compound of 中間 (midterm, middle) and 考査 (examination, test).