"Even" is a good English translation of vabDot in a number of contexts. It's not the only definition of vabDot, but I think it's okay as part of the definition.

But there's a little more to it than that. It's used to say that something is unexpected or surprising or counterintuitive, not just additional. For something that's just additional, you'd probably use je "also."

Grammatically, vabDot is considered an adverbial. (qepHom 2017).

qep'a' 25/2018: Marc Okrand expanded on the meaning of this word, adding the glosses of "moreover" and "in addition".