大四：指大学四年级的学生或者是大学四年级的学习阶段。
Fourth year, also known as S4, is the fourth year of schooling in Scottish, Venezuelan, Ecuadorian, Colombian, and other Latin American countries secondary schools, and is roughly equivalent to Year 11 in England and Wales and Year 12 (Fifth Form) in Northern Ireland. In Latin American countries, it is equal to the United States high school's senior year, but the Scottish S4 is equivalent to 10th grade.
They are semi-finalists for the fourth year in succession.
这是他们连续第四年打入半决赛。
He has just begun his fourth year in hiding.
他刚刚开始他东躲西藏的生活的第4个年头。
The world’s auto industry will suffer a fourth year of poor sales in 2011.
2011年，世界汽车工业将会遭遇到第四个销售低迷的年份。
The number of Japanese students in the United States decreased for the fourth year, to just over twenty-nine thousand.
VOA : special.2009.11.26
More than one-fourth of the four million newborns who die each year around the world were born too early.
VOA : special.2009.10.19
This year's National Cherry Blossom Festival is set for March twenty-seventh through April fourth.
VOA : special.2010.02.23
But Mr Blunkett refused to pay the fourth-year fee for English-based students going north.
For example, Andrew Hsu, mentioned above, dropped out of Stanford University at 19 as a fourth-year neuroscience doctorate candidate.
Will Lesley, a fourth-year doctoral student in religion, tune in when the Crimson play Arizona for a spot in the Sweet 16 on Saturday?