This is the 313th most frequent Chinese word.
大学
University.
In this sentence, '大学' refers to a university or college institution, specifying the level of education.
他上大学的时候学习了工程学。
He studied engineering when he attended university.
Here, '大学' refers to a specific university, being described in terms of its reputation and characteristics.
这是一所著名的大学，吸引了很多留学生。
This is a prestigious university, attracting many international students.
In this example, '大学' refers to the time period or experience of attending university, reflecting a phase in someone's life.