A veil is a soft dynamic cover. In this sense, the word applies well to the description of the dynamic palatine intersection that is capable of opening up the digestive way to the pharynx, while covering the passage to the nose. It acts as a veil, in the way of its functional movements.
Yes, Jan. Quite so. But it also carries the double meaning of a veil, as proposed previously. So, with your contribute, we get "a soft tissue with the function of covering".
In antiquity, the term "velum" was used for a canvas or a door curtain for covering the entrance. So I agree very much with Marias explanation of the terms meaning.