| the offspring of a zebra and a donkey. |
| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |
| Michelson (mī'kəl-sən) Pronunciation Key
German-born American physicist who (with Edward Morley) disproved the existence of ether, the hypothetical medium of electromagnetic waves. Their work served as the starting point for Albert Einstein's development of the theory of relativity. |