passing university entrance exams in the last year of high school (without a gap year)
Refers to a high school student who passes university entrance exams during their final year, entering university immediately after graduation, as opposed to taking a gap year (浪人).
He entered the University of Tokyo straight from high school.
I'm studying every day aiming to pass the entrance exams without a gap year.
A student who has graduated from high school but is taking a gap year to study for university entrance exams, as opposed to 現役合格 which means passing without a gap year.
Compound of 現役 (currently enrolled, active duty) and 合格 (passing an exam).