question mark: Word of the day for September 24, 2020

question mark , n :
(typography) The punctuation mark "?", used at the end of a sentence to indicate a question. (figurative, informal) A state of doubt or uncertainty. (figurative, informal) An enigmatic, inscrutable, or mysterious person or thing; an enigma, a riddle. Polygonia interrogationis, a North American nymphalid butterfly with a silver mark on the underside of its hindwing resembling a question mark (sense 1). Today is National Punctuation Day in the United States, a celebration established by Jeff Rubin in 2004 to promote the correct use of punctuation.