A small container that is propelled, usually pneumatically or hydraulically, through a tube into a nuclear reactor; used to expose samples to the radiation, especially neutron flux, then remove them rapidly for measurements of radioactive atoms having short half-lives. Also known as shuttle.

A small plug driven by pressure through a flow line to clean the line or to check that it is unobstructed.

Any of a large number of burrowing mammals in the family Leporidae.