UNA "REUNIÓN" IS NOT A "REUNION"
Most of my students know that the translation of "reunion" (Spanish) is a "meeting" but the word "reunion" can also be used in English but in a different and more specific context which many Spanish speakers are not aware of.
The word "reunion" is mostly used when you are planning to meet up with a group of people that you have not seen in a long time.
A good example of this is when you meet with old friends from your school 10 years after having graduated. It is normally a special celebration that is well organised and everyone is invited.
Hope that helps!
Soy el director de Daniel Smith + Partners. Tengo más de 10 años de experiencia enseñando inglés a españoles.