an extraordinary or unusual thing, person, or event; an exceptional example or instance.
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.
1865, originally, and usually, figurative, "sour, harsh, severe" (of speech, manners, etc.), from L. acerbus "harsh to the taste, sharp, bitter, sour" (see acerbity).