valve

valve [-s] n

adaptation < L. valva, leaf of a door.

1. Shell; case; pericarp; outer coat; seed vessel; covering of a capsule; leaflet of the calyx and corol in a plant; [fig.] bloom; blossom; flower.
2. Door; access; covering; portal; partition; one-way outlet; uni-directional communication; [fig.] eyelid; [metaphor] vault; concrete burial container.