A lot of the time, the definitions peculiar to a subfield of science _don't_ require much or any additional technical background to understand. They're just abbreviations for special cases that frequently occur in the subfield.

Looking this sort of thing up on the fly in lecture is a great use for LLMs. You'll lose track of the lecture if you go off to find the definition in a reference text. And you can check your understanding against the material discussed in the lecture.