regression

noun

re·​gres·​sion ri-ˈgre-shən 

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

Synonyms

• reversion

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

While not a guarantee, that figure indicates that a regression in the win/loss column over the second half of the year is likely unless the team can perform better. —Max Dible, MSNBC Newsweek, 27 Oct. 2025

Using logistic regression, the researchers identified factors that increased the odds of persistent symptoms. —New Atlas, 25 Oct. 2025

This year, several East teams are in danger of regression. —Lev Akabas, Sportico.com, 21 Oct. 2025

Here’s my Monday piece on Tua Tagovailoa’s regression and notes by position on offense. —Barry Jackson, Miami Herald, 20 Oct. 2025

Word History

First Known Use

1583, in the meaning defined at sense 1

Phrases Containing regression

• linear regression
• multiple regression

Rhymes for regression

• accession
• aggression
• compression
• concession
• confession
• depression
• digression
• discretion
• expression
• impression
• obsession
• oppression

Kids Definition

regression

noun

re·​gres·​sion ri-ˈgresh-ən 

: an act or the fact of regressing

Medical Definition

regression

noun

re·​gres·​sion ri-ˈgresh-ən 

: 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