Juniors and Undergrad

Undergrad and juniors are semantically related. in person actively learning topic. In some cases you can use "Undergrad" instead a noun "Juniors", when it comes to topics like person studying at university.

Undergrad noun - A university student who has not yet received a first degree.

Juniors and undergrad are semantically related. Sometimes you can replace term "Juniors" with "Undergrad", this nouns are similar.