| a bell-shaped glass jar or cover for protecting delicate instruments, bric-a-brac, or the like, or for containing gases or a vacuum in chemical experiments. |
| a novel (1963) by Sylvia Plath. |
| bell jar n. A cylindrical glass vessel with a rounded top and an open base, used to protect and display fragile objects or to establish a vacuum or a controlled atmosphere in scientific experiments. |
