大学一年级的英文表达可以是 "first-year university student" 或者 "first-year college student"。这两种表达都来源于英语中对学生年级的描述方式。"First-year" 指的是大学中的第一年级学生，而 "university" 和 "college" 都指的是大学的意思。

下面是一些例句：

I'm a first-year university student studying engineering.

My sister is a first-year college student at a university in California.

I'm really excited to start my first year at university.

I'm looking forward to meeting other first-year students at orientation.