I think we all know the feeling. The professor is lecturing about some new concept in mathematics and she uses some term that we've never heard of before. And worst of all, everyone is nodding as if they understand what that word meant. Maybe they actually have heard it before, but more likely we are all just nodding because we all don't even know what we should ask about.
Hopefully it doesn't happen too often, but when it does, hopefully I've been in your shoes before. I am trying to make a relatively comprehensive catalog of common and less-common terms in math, and then making videos defining and describing these terms and concepts. It is always growing, and if you feel I have missed an important term, let me know!
For your ease, I have organized the videos I have made alphabetically by the term.