| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
| Rayleigh (rā'lē) Pronunciation Key
British physicist whose investigation of the densities of gases led to his discovery (with Sir William Ramsay) of the noble gas argon in 1894. For this work he won the 1904 Nobel Prize for physics. |