Cyrille, the term wasn't used to describe our equipment until the comopound bow came along. So if we are looking in the proper context, it means anything except compound bows.
That being said, it is the most corrupted term in the sport right now. No two people can say what it means, so it is virtually useless in proper conversation. They were using fiberglass in the very early 1950's...actually right after WWII.
If you look at a bow, and it has a string joining the two ends, and no other accouterments to help draw it...like wheels or cables...than you have a conventional bow. It should be simple, but humans have a way to screw-up a junk yard, so I don't expect any resolution. I call mine recurves and longbows
Don't spend any of God's valuable time pondering terms. I can tell you that is not time well spent. Let someone else worry about such silly things while you are shooting stumps or chasing game.