When you compile the definitions for every letter, have you considered not ordering them alphabetically? (controversial suggestion I know)
When I was studying and came across an alphabetised list, I found it confusing and meaningless because all the connections between terms were missing, and related/contrasting terms were flung about into different sections. An example that stuck me just from your Part 1 was that nobody should be reading about alpha testing without beta testing right next to it. Also it would be helpful to have some sort of categorisation that puts availability testing as a type of non-functional testing, whereas automated testing is a way of doing certain kinds of testing. Otherwise any beginner will find it very hard to get an understanding of how testing works as a practice.