Scepticalscribe,
Maybe it is a difference between American English and UK English but isn't "vocabulary" in the way you used it uncountable (or a non-count noun)?
Mecha
Sorry.
Maybe I am just tired, but I don't understand what you are trying to say.
What do you mean by an 'uncountable' noun?
But, yes, I will admit that sometimes, I feel I need a translator to explain some of the terms and phrases and - even vocabulary - used in American English.
Actually, this - keeping abreast of changes in the language - is one of the things I find most instructive about my membership of this forum; ever since I left the groves of academe, I have lost touch with the way young people speak, the sort of slang they use, and how they use argot to explore, test, challenge and change the language. My students used to be wonderful - and wonderfully generous - educators in the minutiae of contemporary dialect.