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

As conditions change, these two forms merge into a single phase at the critical point.

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

Still, Buttler and English cricket as a whole stand at a critical point, almost 5,000 miles from home.

From BBC • Mar. 4, 2026

But this misses a critical point: The Epstein file dump is not simply playing out as a backdrop against which other acts of American lawlessness are occurring.

From Slate • Feb. 12, 2026

Friederich was obliged finally to give up the siege, because he learned of the fall of Glatz, the critical point of his new conquests.

From "Slaughterhouse-Five" by Kurt Vonnegut

Related Words

• turning point