on the cusp
idiom

- at the point when something is about to change to something else

- the dividing line between two very different things

Merriam-Webster / The Cambridge Dictionary

—
PHRASE ORIGIN

The word "cusp" comes from Latin and specifically derives from the word cuspis, which means "point, spear, pointed end".

The earliest known use in English dates back to the late 1500s with meanings in:

(1) Astronomy — referring to the pointed ends or "horns" of a crescent moon

(2) Geometry — a point on a curve where the tangent line is vertical and the curve changes from being concave-up to concave-down (or vice versa)

The figurative meaning of "on the cusp of" emerged in the late 19th century to indicate being on the brink, threshold, or verge of some change, new development, or important period.

1883: "The poor old lady was on the cusp of her 80th year."

1903: "At this precise moment England is on the cusp of a decidedly different epoch."

1955: "Mankind stands on the cusp of the nuclear age."

—
THE EIFFEL TOWER’S GERMAN ROOTS

On the cusp of its 135th anniversary, the iconic Eiffel Tower in Paris has a little-known secret — its creator's German ancestry.

Patriotic Frenchmen (and women), not noted for their love of Germany, may be less than thrilled to learn the source of the name of the famous landmark on the southern bank of the Seine River in Paris.

The 300 metre Eiffel Tower was built by Alexandre Gustave Bönickhausen. Before moving to Paris from Eifel, Germany, he changed his surname to “Eiffel” because his friends could not pronounce his German name!

—
SYNONYMS

about to, advent (of), approaching (a critical juncture), at the brink of, at the dawn of, at the edge/precipice/threshold of, at the tipping/turning point, bordering on, close to, drawing near to, edging towards, nearing, ON THE CUSP (of), on the brink/doorstep/verge of, on the horizon, poised for (to), ready to break, teetering on the brink (edge of), tiptoeing toward, verging on

—
SMUGGLE OWAD into an English conversation, say something like:

“With artificial intelligence we are ON THE CUSP of a revolution in medical diagnostics and treatment.”

—
Every month, my family and I spend evening and weekend hours researching and writing your daily OWAD. It remains FREE, AD-free, and ALIVE thanks to voluntary donations from appreciative readers. If you aren’t already, please also consider supporting us - even the equivalent of a single cup of coffee a month will help us cover mailing, site hosting, and maintenance costs. Just head over to our secure DonorBox page:

https://donorbox.org/please-become-a-friend-of-owad-5-3

or bank transfer to Paul Smith
IBAN: DE75 7316 0000 0002 5477 40
Please use your email-address as ‘Verwendungszweck’

Thanks so much,

Paul Smith
(OWAD-Founder)

New Seminar! 1-day “Intelligent English" with Paul & Helga Smith: https://owad.de/intelligent-english