the.com/velum

means The soft, muscular flap at the back of the roof of your mouth that rises or lowers to direct air and sound into your mouth or your nose.

from From Latin 'velum,' meaning 'veil,' 'sail,' or 'curtain' — the same word Romans used for a ship's sail or a covering cloth. Anatomists borrowed it because the soft palate hangs like a little curtain at the back of the mouth, and its muscular cousin 'velar' (as in velar consonants, sounds made by lifting this flap toward the back of the tongue) comes from the same root.