re·​gres·​sion | \ ri-ˈgre-shən How to pronounce regression (audio) \

Definition of regression

1 : the act or an instance of regressing
2 : a trend or shift toward a lower or less perfect state: such as
a : progressive decline of a manifestation of disease
b(1) : gradual loss of differentiation and function by a body part especially as a physiological change accompanying aging
(2) : gradual loss of memories and acquired skills
c : reversion to an earlier mental or behavioral level
d : a functional relationship between two or more correlated variables that is often empirically determined from data and is used especially to predict values of one variable when given values of the others the regression of y on x is linear specifically : a function that yields the mean value of a random variable under the condition that one or more independent variables have specified values
3 : retrograde motion

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Synonyms & Antonyms for regression


retrogression, reversion


advancement, development, evolution, progression

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Examples of regression in a Sentence

the regression to really childish behavior that boys often undergo when put in large groups

Recent Examples on the Web

Allen needs Wommack’s best to reverse last season’s defensive regression enough to give IU the platform for another bowl berth, and Allen is willing to give his defensive coordinator room to work. Zach Osterman, Indianapolis Star, "Why Kane Wommack is the man Tom Allen handpicked to run IU's defense," 6 Sep. 2019 Gonzales has a point about defensive regression in the second half. Jeff Metcalfe, azcentral, "ASU defense loses shutout but benefits from new punting star Michael Turk," 30 Aug. 2019 Shortstop Brandon Crawford’s regression at the plate may compel the front office to urge Bochy to audition prospect Mauricio Dubón up the middle. Kerry Crowley, The Mercury News, "Will the Giants’ definition of ‘meaningful baseball’ change in September?," 23 Aug. 2019 But given the Loons’ current third-place standing in the Western Conference, simply making one of the top seven seeds at the end of the year would be a regression at this point. Andy Greder, Twin Cities, "Minnesota United’s new goal: hosting an MLS Cup playoff game," 13 Aug. 2019 His only negative last year was the regression in his rushing ability (46/148/0). Shawn Childs,, "Andrew Luck 2019 Fantasy Football Player Profile," 12 Aug. 2019 Mariota’s regression in 2017 and 2018 has created some doubt within the franchise going into the fifth and final season of his rookie contract., "Is Marcus Mariota’s future in doubt? 10 questions for the Tennessee Titans as training camp opens," 30 July 2019 Those regressions have offset the impressive strides made by players such as shortstop Xander Bogaerts, catcher Christian Vazquez and third baseman Rafael Devers. Dave Sheinin,, "2018 Red Sox rarely knew desperation; 2019 team knows nothing but," 18 July 2019 The zoo is concerned that delaying the transfer will interfere with the bond Ndume has made with Cincinnati staff and cause regressions in his training. Cameron Knight,, "Gorilla Ndume's trip home delayed due to worries over risks, courts asked to decide," 5 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'regression.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of regression

1583, in the meaning defined at sense 1

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Statistics for regression

Last Updated

12 Sep 2019

Look-up Popularity

Time Traveler for regression

The first known use of regression was in 1583

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More Definitions for regression



Financial Definition of regression

What It Is

Regression is a statistical method used in finance and other fields to make predictions based on observed values. It is a measure of how correlated a group of actual observations are to a model’s predictions.

How It Works

In the following examples, the blue dots represent the going prices for figurine collections on eBay. Collections with more figurines go for as much as $100; collections with fewer than five figurines sell for very little. How can we predict how much a collection will sell for?

We do it using regression analysis, which essentially finds the formula for the line that most closely fits the observations. That way, we can use the line to predict what the price of the collection might be if we know how many figurines are in a collection, or we can predict how many figurines should be in a collection if we know the asking price.

In our example below, the black lines represent a regression line, which is represented by the formula in the top right-hand corner of each chart. This formula is what analysts also use to predict future values of securities based on the behavior of the actual observations.

Goodness of fit is a component of regression analysis. The term refers to how far apart the expected values of a financial model are from the actual values (that is, how predictive the line is).

As you can see, this regression line has a high goodness of fit; the formula for the regression line comes up with the observed values about 79% of the time.

This next chart is an example of a regression line with low goodness of fit. Here, the values are all over the place, and the formula for the regression line was virtually unable to predict anything.

Why It Matters

Regression is a mathematical version of a crystal ball, but a very cracked, blurry crystal ball. Goodness of fit is the key -- it's a confidence measure. This is because when you've come up with a formula that accounts for most of the variations in a group of, say, price observations, you've also come up with a formula that can be a very reliable predictor of what prices will be in the future. And that’s priceless.

Source: Investing Answers


re·​gres·​sion | \ ri-ˈgresh-ən How to pronounce regression (audio) \

Medical Definition of regression

: a trend or shift toward a lower, less severe, or less perfect state: as
a : progressive decline (as in size or severity) of a manifestation of disease tumor regression following radiation
b(1) : a gradual loss of differentiation and function by a body part especially as a physiological change accompanying aging menopausal regression of the ovaries
(2) : gradual loss (as in old age) of memories and acquired skills
c : reversion to an earlier mental or behavioral level or to an earlier stage of psychosexual development in response to organismic stress or to suggestion a protective regression towards childhood— Havelock Ellis

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Comments on regression

What made you want to look up regression? Please tell us where you read or heard it (including the quote, if possible).


one from the Upper Peninsula of Michigan

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