critical point

American  

[krit-i-kuhl point] / ˈkrɪt ɪ kəl ˈpɔɪnt /

noun

1. Physics. the point at which a substance in one phase, as the liquid, has the same density, pressure, and temperature as in another phase, as the gaseous.

   The volume of water at the critical point is uniquely determined by the critical temperature.

2. Mathematics.

   1. (of a function of a single variable) a point at which the derivative of the function is zero.

      One critical point, at x = 0, is a decreasing function for positive x.

   2. (of a function of several variables) a point at which all partial derivatives of the function are zero.

      Find and classify all the critical points of the given function.

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critical point British  

noun

1. physics

   1. the point on a phase diagram that represents the critical state of a substance

   2. another name for critical state

2. maths the US name for stationary point

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critical point Scientific  

1. Physics The temperature and pressure at which the liquid and gaseous phases of a pure substance become unstable and fluctuate locally within the substance. The critical point of water is at a temperature of 374°C (705.2°F) and a pressure of 218 atmospheres, at which point it becomes opaque.

2. Physics Compare triple point

3. Mathematics

   1. A maximum, minimum, or point of inflection of a curve.

   2. A point at which the derivative of a function is zero, infinite, or undefined.

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Etymology

Origin of critical point

First recorded in 1875–80

Example Sentences

At Monday's announcement in Ottawa, Carney said that Canada was at a critical point in its history due to its changing relationship with the US, requiring it to invest and build at an urgent pace.

From BBC • Apr. 27, 2026

Beyond the critical point, water enters a supercritical state, and under everyday conditions, it already exists in this regime.

From Science Daily • Mar. 29, 2026

“The deal brings a binding commercial anchor to the R2 platform and injects capital visibility at a critical point in the production cycle while also validating its autonomous vehicle roadmap,” the analysts say.

From The Wall Street Journal • Mar. 20, 2026

"This could potentially hamper US warfighters at a critical point in time."

From Barron's • Mar. 11, 2026

At the critical point, the imagination makes connections between seemingly unrelated parts and recombines them.

From "History of Art, Volume 1" by H.W. Janson

Related Words

• turning point