unknown quantity

noun

: someone or something whose abilities or characteristics are not yet known

If you've never been published before, you're an unknown quantity, so you're going to have difficulty selling your first novel.

Examples of unknown quantity in a Sentence

Recent Examples on the Web

One of the challenges was that the Nazis were producing an unknown quantity of new tanks that were more powerful than older models. — Manon Bischoff, Scientific American, 7 July 2026

The co-host will be confident of putting in a repeat performance against an Australian side that is a bit of an unknown quantity. — Ben Church, CNN Money, 19 June 2026

Trump’s pick to chair the Federal Reserve is, in the words of University of Virginia economics professor Eric Leeper, an unknown quantity — and markets are pricing in the uncertainty. — Nick Lichtenberg, Fortune, 27 May 2026

The real Colbert, not the character, would helm the show, and that guy behind the mask was still an unknown quantity to the viewing public. — Lorraine Ali, Los Angeles Times, 20 May 2026