known quantity

American  

noun

1. Mathematics. a quantity whose value is given: in algebra, frequently represented by a letter from the first part of the alphabet, as a, b, or c.

2. any factor, circumstance, etc., that is already accepted or familiar.

   Her honesty is a known quantity.

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Etymology

Origin of known quantity

First recorded in 1975–80

Example Sentences

Mr. Farage is a known quantity after more than a decade in the spotlight following his leadership of the successful referendum campaign to leave the European Union in 2016.

From The Wall Street Journal • May 8, 2026

Todd Blanche is a known quantity in Trump World.

From Salon • Apr. 22, 2026

As such, Warsh is a known quantity in upper-echelon social, political, and economic circles.

From Barron's • Feb. 2, 2026

Now a known quantity, Saints reduced their kicking to Caluori to deal with the breakout star's freakish aerial ability, while the teenager struggled to get the ball in hand to show his running power.

From BBC • Oct. 27, 2025

With a little attention it will not be difficult to prepare the paper so as to have a known quantity of coloring matter in a square of a given size.

From Paper and Printing Recipes A Handy Volume of Practical Recipes, Concerning the Every-Day Business of Stationers, Printers, Binders, and the Kindred Trades by Ford, J. Sawtelle