|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a gadget; dingus; thingumbob.|
|Fresnel (frā-něl') Pronunciation Key
French physicist whose investigations of the interference, diffraction, and polarization of light helped establish the theory that light moves in a wavelike motion. Fresnel also made great contributions to the field of optics, including the development of a compound lens for use in lighthouses.