| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
| the offspring of a zebra and a donkey. |
| Doppler (dŏp'lər) Pronunciation Key
Austrian physicist and astronomer who in 1842 explained the effect, now named for him, of variations in the frequency of waves as a result of the relative motion of the wave source with respect to the observer. |