英和和英

名詞

unknown quantity (複数形 unknown quantities)

1. (idiomatic) A person or thing whose nature or value is a mystery.
   • 1895 October 1, Stephen Crane, chapter 1, in The Red Badge of Courage, 1st US edition, New York: D. Appleton and Company, page 14:

     Whatever he had learned of himself was here of no avail. He was an unknown quantity.

   • 1907, The Bookman, vol. 25, p. 166 (Google snippet view):

     . . . the Evening Post of this city to refer to him recently as "the young Belgian painter," and to the general public he is an unknown quantity.

   • 1963 June, “Beyond the Channel: France: High-power diesels”, in Modern Railways, page 417:

     The big French diesel is something of an unknown quantity, whereas many French-built electric locomotives developing 3,000 h.p. and more have been well proved in service.

   • 1982 Sep. 22, Henry Tanner, "Gemayel Brothers Assessed in Syria," New York Times (retrieved 9 Jan 2016):

     Amin Gemayel, it is felt here, is an unknown quantity and it is impossible to predict how he will act.

   • 2015 Dec. 6, "Congratulations on 10 years, David Cameron - but don't rest on your laurels," Telegraph (UK) (retrieved 9 Jan 2016):

     [H]e was still an unknown quantity – a young, untested figure.

   Antonyms: known quantity, household name

2. Used other than figuratively or idiomatically: see unknown,‎ quantity.
   • 2012 January 1, Richard N. Aufmann, Joanne Lockwood, Beginning Algebra‎^[1], Cengage Learning, →ISBN, page 77:

     Many of the applications of mathematics require that you identify an unknown quantity, assign a variable to that quantity, and then attempt to express another unknown quantity in terms of that variable.

   • 2016, Steve Pace, The Projects of Skunk Works: 75 Years of Lockheed Martin's Advanced Development Programs‎^[2], Voyageur Press, →ISBN, page 145:

     So promising was the Skunk Works' stealth cruise missile offering, the USAF ordered an unknown quantity of these missiles under a highly classified program dubbed Senior Prom.