英語詞典中是這樣解釋的 (of pupils，etc) fail to go up to the next grade (year)；repeat the year's work；
正式表達中 可以用retardation
交流中相關表達有：
study in the same grade;
repeat the year's work;
remain in the same grade;
to stay down;
留級生的表達是 detained student
輟學：discontinue one's studies 動詞詞組是 drop out
相關表達：
For teenagers, pregnancies, alcoholism, drugs and dropouts are all part of the same sad resume.
懷孕、酗酒、吸毒和輟學是許多青少年悲慘的***同經歷。