: point, apex: such as
: 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
: either horn of a crescent moon
: a fixed point on a mathematical curve at which a point tracing the curve would exactly reverse its direction of motion
: an ornamental pointed projection formed by or arising from the intersection of two arcs or foils (see foil entry 2 sense 4)
: a point on the grinding surface of a tooth
: 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 Fortune’s very first issue, published in February of 1930, came on the cusp of the Great Depression. Alan Murray, Fortune, 26 Apr. 2024 The two sides seemed at the cusp of a deal in the summer of 2022; the Iranian negotiators took it back to Tehran, where new demands were added and the entire process fell apart. David E. Sanger, New York Times, 15 Apr. 2024 See all Example Sentences for cusp 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cusp.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin cuspis point

First Known Use

1585, in the meaning defined above

Time Traveler
The first known use of cusp was in 1585

Dictionary Entries Near cusp

Cite this Entry

“Cusp.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cusp. Accessed 24 May. 2024.

Kids Definition


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

Medical Definition


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

More from Merriam-Webster on cusp

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