high school graduate studying for university entrance exam retake
Refers to someone who has graduated from high school but did not pass their desired university entrance exams and is now studying to retake them, often while not enrolled in any school. The term 浪人 (ronin) originally meant a masterless samurai, and by extension a student without a school affiliation.
He attended a prep school for a year as a ronin student.
Life as a ronin student is said to be mentally tough.
浪人 broadly means a masterless samurai or, in modern context, a student without a school affiliation. 大学浪人 specifically refers to a student preparing to retake university entrance exams.
予備校生 is a student enrolled in a preparatory school, which may include high school students or ronin. 大学浪人 emphasizes the status of having graduated high school and not being enrolled in a university.
Compound of 大学 (university) and 浪人 (ronin, originally 'masterless samurai', later extended to mean a student without a school affiliation). The term reflects the historical metaphor of a ronin as someone between affiliations.