WordNet sense 1 (membrane of the young sporophore of various mushrooms extending from the margin of the cap to the stem and is ruptured by growth; represented in mature mushroom by an annulus around the stem and sometimes a cortina on the margin of the cap):

WordNet sense 2 (membrane initially completely investing the young sporophore of various mushrooms that is ruptured by growth; represented in the mature mushroom by a volva around lower part of stem and scales on upper surface of the cap):

WordNet sense 3 (a muscular flap that closes off the nasopharynx during swallowing or speaking):