: point, apex: such as
a
: a point of transition (as from one historical period to the next) : turning point
also : edge, verge
on the cusp of stardom
… you're on the cusp between heat exhaustion and life-threatening heatstroke. Mark Jannot
b
: either horn of a crescent moon
c
: a fixed point on a mathematical curve at which a point tracing the curve would exactly reverse its direction of motion
d
: an ornamental pointed projection formed by or arising from the intersection of two arcs or foils (see foil entry 2 sense 4)
e(1)
: a point on the grinding surface of a tooth
(2)
: a fold or flap of a cardiac valve
cuspate adjective
cusped adjective

Illustration of cusp

Illustration of cusp
  • 1 cusp d

Examples of cusp in a Sentence

the cusp of a tooth medical researchers who are on the cusp of a major breakthrough
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Danielle Scott, a legally blind Afro-Cuban, Polish-Jewish, and Asian mixed-media artist at the cusp of international fame, risks her own well-being by exposing herself to the intergenerational trauma of the Atlantic Slave Trade. Matthew Carey, Deadline, 7 May 2025 That journey, which has already seen the top pick of the 2021 draft endure a major injury and historic losing, earn an All-Star bid and lift the Detroit Pistons back to the playoffs, led him to the cusp of his defining moment. Hunter Patterson, New York Times, 28 Apr. 2025 Along with fellow senior transfers Sedona Prince and Madison Conner, Van Lith helped take a TCU program that had never won more than 25 games in a season to 33 wins and the cusp of the Final Four. Everett Cook, Axios, 28 Mar. 2025 Nashville has sprinkled some cayenne pepper on more than just its fried chicken of late though, spicing up its game and winning four matches in a row to reach the cusp of a season-long string of victories. Andrew Knoll, Orange County Register, 13 Mar. 2025 See All Example Sentences for cusp

Word History

Etymology

Latin cuspis point

First Known Use

1585, in the meaning defined above

Time Traveler
The first known use of cusp was in 1585

Cite this Entry

“Cusp.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cusp. Accessed 10 Jul. 2025.

Kids Definition

cusp

noun
: a point or pointed end or part: as
a
: either of the pointed ends of a crescent moon
b
: a point on the grinding surface of a tooth
c
: a fold or flap of a heart valve

Medical Definition

cusp

noun
1
: a point on the grinding surface of a tooth
2
: a fold or flap of a cardiac valve
cuspal adjective

More from Merriam-Webster on cusp

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!