| a gadget; dingus; thingumbob. |
| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
piston (pĭs'tən) Pronunciation Key
(click for larger image in new window) A solid cylinder or disk that fits snugly into a hollow cylinder and moves back and forth under the pressure of a fluid (typically a hot gas formed by combustion, as in many engines), or moves or compresses a fluid, as in a pump or compressor. |