There are three questions tagged with vocabulary-building. The tag should be deleted, and the questions tagged with vocabulary.
So far as I can tell, this has been done.– tchrist ModSep 11, 2016 at 16:18
I'm not sure I know what either of those mean.
Likewise for words .
There are hardly any "vocabulary-building" ones, so I'd just delete those (or reduce to vocabulary.
We probably don't need both words and vocabulary, and possibly neither.