Thank you for the suggestions! Sorry for the late feedback on this one.
My brain is dead these days, and I didn't feel apt to follow up on that one.
Yes, exactly : I'm looking for something wiki-like, but for Word : putting a term inside [ ] (in my case, it would probably be [[ ]] to avoid confusion with comments) would transform it into a potential link -- as Iphigenie explained.
@tabletguy : I'm not sure how you'd transform the "Chinese tone marking converter" macro into one that would have a wiki bend...
The macro would probably have to :
1- Find the bracketed words
2- Create a database or index (or use an already existing one -- there are so many desktop search software around...) to contain all these bracketed words (the wiki words), and, of course, refer back to the exact spot in the documents containing the original bracketed words (a bit like tiddlyWiki, for example -- but I have no idea how tiddlyWiki does it...)
3- Rapidly find corresponding "normal" words in MS Word documents and link them back to the original (bracketed) term (thanks to the "wiki word" database/index).
...or something like that... I'm thinking out loud, of course.
I have no idea how complex that would be to code, or if it even exists. Maybe it does.
edit : the nice thing with wiki words is that your can quickly refer back directly to
the definition you want for a specific term, without having to spend time looking for it manually into a data base (or, even worse, using X1, or something else...) -- it's not just mere linking similar words together, of course. Inserting tags-keywords (as textual strings) directly in the text could do the trick, I guess, but would certainly not be as elegant, and would be more complicated to handle with large quantities of terms/tags.