This is the 543rd most frequent Chinese word.
系
"系" means "system," "department," "connection," or "to tie/link."
In this sentence, '系' refers to a department within an academic institution, such as a faculty or a division.
他是计算机系的学生。
He is a student in the computer science department.
In this usage, '系' means 'to fasten' or 'to tie', referring to securing an object, like a belt.
我们需要系好安全带。
We need to fasten our seat belts.
Here, '系' serves as a literary word meaning 'lies in' or 'is rooted in', often used in more formal contexts to indicate a connection.