cusp

noun

ˈkəsp 

: 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

ˈkə-ˌspāt 

-spət

adjective

cusped

ˈkəspt 

adjective

Illustration of cusp

• 1 cusp d

Synonyms

• brink
• edge
• point
• threshold
• verge

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

Yet in less than six months of war it has been pushed to the cusp of famine, a process that usually unfolds over years. —Hazem Balousha, Washington Post, 4 Apr. 2024

Using the standard chart, the lens scores right at the cusp of the excellent range for the 45MP EOS R5 sensor at 200mm f/6.3-11 (3,700-4,100 lines). —PCMAG, 22 Mar. 2024

How did Michigan get to the cusp of a national title? —Tony Garcia, Detroit Free Press, 7 Jan. 2024

There’s no time like the cusp of the new year to start checking out fresh luggage options for your upcoming trips, and the Samsonite Omni 2 Hardside suitcase has been on my radar for a while. —Merrell Readman, Travel + Leisure, 26 Dec. 2023

These solutions will substantially lower the barriers to 5G deployment, offering Dell a competitive edge in a market at the cusp of exponential growth driven by the global rollout of 5G technology. —Steve McDowell, Forbes, 26 Feb. 2024

Kalen DeBoer, who lifted Washington from four wins to the cusp of a national championship in two seasons, accepted Alabama’s offer on Friday. —Jon Wilner, The Mercury News, 12 Jan. 2024

From his early childhood to the cusp of a half-century, Black Thought presents an origin story on par with his superhero status in the hip-hop multiverse. —Ron Hart, SPIN, 8 Dec. 2023

The remote island that straddles the cusp of the Caribbean and the Atlantic is just a 20 minute flight from Providenciales (and is not to be confused with the Belize island Ambergris Caye). —Shannon McMahon, Condé Nast Traveler, 10 Oct. 2023

Word History

Etymology

Latin cuspis point

First Known Use

1585, in the meaning defined above

Phrases Containing cusp

• on the cusp

Kids Definition

cusp

noun

ˈkəsp 

: 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

ˈkəsp 

1

: a point on the grinding surface of a tooth

2

: a fold or flap of a cardiac valve

cuspal

ˈkəs-pəl 

adjective