Being smart won't help, unless it leads you to research some; it's a
lingo thing...
Terminal shoot meristems is basically the main (apical) growing shoot.
witch's broom is a condition where loads of stems all bunch up together to form what looks like, wait for it... a witches broom. Different things cause it with different plants. It's quite common with berry bushes.
Lots of things in the plant kingdom sound like they come straight out of a fairy tale.
Or is it the other way around?
-mu