That's not exactly the description I would go with for a woomera. The woomera is not thrown, and acts as an extension of the arm when throwing a spear. A boomerang is more likely to be used for flocks of birds, so the definitions may have been mixed up.
People might know it better as an _atlatl_. Generically, it’s a “spear-thrower”. It’s amazing how much difference they make - good fun to make in the backyard!