critical point


noun

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.
Mathematics.
  1. (of a function of a single variable) a point at which the derivative of the function is zero.
  2. (of a function of several variables) a point at which all partial derivatives of the function are zero.

Nearby words

  1. critical density,
  2. critical mass,
  3. critical organ,
  4. critical path analysis,
  5. critical period,
  6. critical pressure,
  7. critical ratio,
  8. critical region,
  9. critical state,
  10. critical temperature

Origin of critical point

First recorded in 1875–80

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019


British Dictionary definitions for critical point

critical point

noun

physics
  1. the point on a phase diagram that represents the critical state of a substance
  2. another name for critical state
maths the US name for stationary point
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for critical point

critical point

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. Compare triple point.
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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.