An unpredictable person or thing, as in We don't know how the new pitcher will do—he's an unknown quantity. This expression comes from algebra, where it signifies an unknown numerical value. Its figurative use dates from the mid-1800s.
What The “X” In “Xbox” Stands For?No letter in the English language gets around like X. The 24th letter of the alphabet shows up everywhere, from the popular Xbox to standing in for a signature on legal documents. It represents a chromosome, signifies the multiplication process, and marks “the spot” on treasure maps. Let’s explore just a few of the uses of this versatile letter. The story behind the X in Xbox …
How The Letter “X” Creates More Gender-Neutral LanguageAs our understanding of gender expands from the binary of male and female to include intersex, nonbinary, and transgender people, we are exploring new ways of describing gender identity and expression—and the letter X has the power to help.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.