The email included several terms that were not in the Glossary.
The simple reason is I've not got round to adding that term yet! I do have several lists of words / terms to add and they will be added in due course (so much to do and so little time!) I have added the ones that were included with this question this week.
In the mean time, if you're puzzling over a term by all means email me and ask away for a speedy inclusion.