# Definition of probability in US English:

## probability

### noun

• 1The extent to which something is probable; the likelihood of something happening or being the case.

‘the rain will make the probability of their arrival even greater’
• ‘In terms of probability, the chance of recombination increases with increase in length of the chromosome arm.’
• ‘It's all in the hands of fate and probability, which our very educational maths classes taught us how to calculate.’
• ‘By the same laws of probability, the chances that a random bus will spontaneously explode for no reason are slim to none.’
• ‘It shows the extent to which this probability would increase with lower, and decrease with higher, screening costs.’
• ‘They will continue to kidnap because probability shows that the chance of being caught and prosecuted in Trinidad is slim.’
• ‘The laws of probability say it cannot happen but Maine Road is still too fresh in the minds of Minstermen everywhere for it to be ignored just yet.’
• ‘He then shows how belief arises with both chance and probability.’
• ‘This holds provided that the initial probability of the hypothesis in relation to the background knowledge or belief is not zero.’
• ‘The probability of this convergence happening by chance tends to zero as the number of experimental procedures increases.’
• ‘He said, ‘In probability it would have happened, so you did it’, and that was it.’
• ‘Simply put, the larger the number of plays, the more likely that the fixed probability will catch up with the player.’
• ‘This step examines each hazard in terms of probability and severity to determine what the level of risk is when you're exposed to the hazard.’
• ‘For these reasons he also believes that the depression would have on the balance of probability been likely to occur in any case, although later.’
• ‘As in most of genetics, breeding good hips is largely a matter of chance, or probability.’
• ‘Not only that but it has the same probability of happening as you buying two winning lottery tickets in one week.’
• ‘This provides increasing probability of recombination and hence increased mapping resolution.’
• ‘I resonate with your point that probability balances out luck as more games are played.’
• ‘It is a known and foreseeable hazard and has high probability.’
• ‘He agreed with the coroner that on the balance of probability it was likely someone else had been in the graveyard when the stone fell on Adam.’
• ‘The probability of that happening is probably somewhat lower than a conventional attack.’
• ‘The probability of transformation is framed entirely in terms of the quality of the commodity.’
• ‘The judge was entitled to conclude that the patentees had lost a chance of making sales to those buyers - no doubt a chance of differing probability in each case.’
likelihood, likeliness, prospect, expectation, chance, chances, odds, possibility
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1. 1.1 A probable or the most probable event.
‘for a time revolution was a strong probability’
‘the probability is that it will be phased in over a number of years’
• ‘The chance that the recent combination of financial events would coincide was a low probability.’
• ‘The common scenarios in general practice all involve weighing up probabilities and accepting varying degrees of uncertainty.’
• ‘If she is young and attractive, the court may consider her remarriage to be a strong probability.’
• ‘The tribunal has established as a probability that the infection was caused by the Armour product.’
• ‘Give us some sense about the probabilities that you are talking about here and what you are looking for.’
• ‘By ‘it is clear’, I mean that the facts establish this as a strong probability.’
• ‘This is only one of the probabilities for us now as we appear to be approaching the predicted end-game.’
• ‘Anyway, there are two probabilities for what could happen between now and polling day.’
probable event, prospect, possibility, fair bet, good bet, reasonable bet
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2. 1.2Mathematics The extent to which an event is likely to occur, measured by the ratio of the favorable cases to the whole number of cases possible.
‘the area under the curve represents probability’
‘a probability of 0.5’
• ‘Among seven people, there is about a 60 percent probability that two will have birthdays within a week of each other.’
• ‘In the field of mathematics he worked on probability, recurring decimals and the theory of equations.’
• ‘When there are twice as many attackers as defenders, the winning probability exceeds 80 percent.’
• ‘The probability of an event is the ratio of the favorable outcomes to the possible outcomes.’
• ‘An event which will definitely occur has probability 1, and everything else is somewhere in between.’

### Phrases

• in all probability

• Used to convey that something is very likely.

‘he would in all probability make himself known’
• ‘Matches between these two teams in recent years have always been close and in all probability that's how it's going to be again on this occasion.’
• ‘I have never hunted, and in all probability will never hunt.’
• ‘There is no need to ask to see the official personally and to take up his time in this way; if appropriate, he will send a message of thanks at a later date, in all probability.’
• ‘So, the one with the sling on his arm and those two were the ones, in all probability, who were treated in Kuwait City.’
• ‘Women with low BMI value and anaemia in the reproductive age will, in all probability, have low birth weight infants.’
• ‘We'll never know now, but the expert view was that the geese were in all probability about to nest and were merely protecting their territory.’
• ‘He has, in all probability, just one chance to achieve the single ambition that remains unfulfilled in his hard-working career.’
• ‘The situation will, in all probability, be aggravated by the summer season, which threatens to be severe this time.’
• ‘The results are not only statistically significant, but in all probability clinically significant.’
• ‘Women tend to blame themselves for the loss, when in all probability there was nothing they could have done to prevent it.’
in all likelihood, in all probability, as likely as not, very likely, most likely, likely, as like as not, ten to one, the chances are, doubtless, no doubt, all things considered, taking all things into consideration, all things being equal, possibly, perhaps, maybe, it may be, presumably, on the face of it, apparently
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### Origin

Late Middle English: from Latin probabilitas, from probabilis ‘provable, credible’ (see probable).

## probability

/ˌprɑbəˈbɪlədi//ˌpräbəˈbilədē/