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

But as interest rates are on cusp of dropping, the bank stock gold rush could be coming to an end. —Michael Del Castillo, Fortune, 16 Sep. 2024

As Oklahoma City ascended from a rebuilding team to the cusp of a contender, Williams was a crucial piece of that happening. —Nick Crain, Forbes, 14 Sep. 2024

This was a moment when soft-landing confidence got a jolt, which would peak a month later at all-time highs above 5660 on the S & P. Fed toss-up Of course, recovering back to the cusp of those old highs means rising to levels where the market has repeatedly failed to find aggressive buyers. —Michael Santoli, CNBC, 14 Sep. 2024

The groom has two brothers: Thomas (Jack Reynor, resurrected from a midsummer ritual), accompanied by his pregnant wife, Abby (Fanning elder Dakota); and Will, on the angry cusp of 18 and sweet on a server. —Raven Smith, Vogue, 11 Sep. 2024

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