Cloche

noun

1. A glass covering, originally bell-shaped, for garden plants to prevent frost damage and promote early growth.
2. A bell-shaped, close-fitting women’s hat with a deep rounded crown and narrow rim.
3. A tableware cover, often resembling a bell.
4. An apparatus used in controlling certain aeroplanes, consisting principally of a steering column mounted with a universal joint at the base, which is bell-shaped and has attached to it the cables for controlling the wing-warping devices, elevator planes, etc.