from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The quality or condition of being probable; likelihood.
  • noun A probable situation, condition, or event.
  • noun The likelihood that a given event will occur.
  • noun Statistics A number, ranging from zero to one, expressing either the projected likelihood that a specific event will occur or the observed ratio of the number of actual occurrences to the number of possible occurrences.
  • idiom (in all probability) Most probably; very likely.

from The Century Dictionary.

  • noun The state or character of being probable; likelihood; appearance of truth; that state of a case or question of fact which results from superior evidence or preponderation of argument on one side, inclining the mind to receive that as the truth, but leaving some room for doubt.
  • noun Quantitatively, that character of an argument or proposition of doubtful truth which consists in the frequency with which like propositions or arguments are found true in the course of experience.
  • noun Anything that has the appearance of reality or truth.
  • noun A statement of what is likely to happen; a forecast: applied in the plural by Cleveland Abbe to his daily weather-predictions in Cincinnati in 1869, and subsequently adopted by General Myer to designate the official weather-forecasts of the United States Signal Service. The same term had been similarly used by Leverrier in Paris since 1859.

from the GNU version of the Collaborative International Dictionary of English.

  • noun The quality or state of being probable; appearance of reality or truth; reasonable ground of presumption; likelihood.
  • noun That which is or appears probable; anything that has the appearance of reality or truth.
  • noun (Math.) Likelihood of the occurrence of any event in the doctrine of chances, or the ratio of the number of favorable chances to the whole number of chances, favorable and unfavorable. See 1st Chance, n., 5.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun the state of being probable; likelihood
  • noun an event that is likely to occur
  • noun the relative likelihood of an event happening
  • noun mathematics a number, between 0 and 1, expressing the precise likelihood of an event happening

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a measure of how likely it is that some event will occur; a number expressing the ratio of favorable cases to the whole number of cases possible
  • noun the quality of being probable; a probable event or the most probable event


from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin probabilitas ("probability, credibility"), from probabilis ("probable, credible"); see probable.


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  • It is a doubt founded on a _positive_ opinion against the existence of the law, or its applicability to the case in point, an opinion fraught with probability, _solid, comparative, practical probability_.

    Moral Philosophy Joseph Rickaby 1888

  • Note that it does not mean it will happen, just that the probability is approaching 1 or unity.

    Cheeseburger Gothic » Prepping for Pucka. 2010

  • Embracing Some Risk Two certified financial planners and a finance professor have come up with a system that manages what they call the "probability of failure."

    How Much Is Too Much? Kelly Greene 2011

  • Whether both mutations happen in one individual, or one in a parent and the next in that individual's offspring, without the benefit of selection to expand the first mutation within the population, the probability is the same.

    Behe's Test, Take 2 2008

  • So, the probability is my child will opt for the Jesus movement.

    Losing My Religion Jessica 2005

  • Two certified financial planners and a finance professor have come up with a system that manages what they call the "probability of failure."

    unknown title 2011

  • So, Hacking argues, what we call probability was not an object of thought that existed in embryo to become fully developed when some social need or technological opportunity encouraged mathematicians to study it more carefully.

    unknown title 2009

  • As long as the probability is not zero, then if the universe is spatially infinite we should expect life to arise somewhere in the infinite universe ….

    A Short Critique of Bradley Monton's Paper 2009

  • The world has not shown me that understanding of elementary probability is widespread, so I worry that these kind of tools will be misused/misunderstood.

    Matthew Yglesias » Bacterial Fingerprints and Bayes’ Law 2010

  • In Uttar Pradesh, a woman has one in 42 lifetime risks of maternal death, the probability is just one in 500 in Kerala, the report says, according to PTI reports.

    Orissa has high neo-natal deaths: Unicef report 2009


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  • "It may be that the race is not always to the swift, nor the battle to the strong - but that is the way to bet."

    --Damon Runyon

    September 27, 2007