incest

American  

[in-sest] / ˈɪn sɛst /

noun

1. sexual intercourse between closely related persons.

2. the crime of sexual intercourse, cohabitation, or marriage between persons within the degrees of consanguinity or affinity wherein marriage is legally forbidden.

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incest British  

/ ˈɪnsɛst /

noun

1. sexual intercourse between two persons commonly regarded as too closely related to marry

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incest Cultural  

1. Sexual relations between relatives who are forbidden by law to marry; for example, between father and daughter or mother and son.

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Though each society has its own system for determining the range of people who fall into this category, every society has an incest taboo of some sort.

Etymology

Origin of incest

1175–1225; Middle English < Latin incestus (noun) sexual impurity, derivative of incestus (adj.) profane, sexually impure ( in- in- ³ + -cestus combining form of castus chaste ), by analogy with v. nouns derived with -tus

Example Sentences

After the movie came out, Lindo says, he met an incest survivor who said she appreciated the humanity he gave to a seemingly monstrous character.

From The Wall Street Journal • Mar. 3, 2026

He added that he fully supports exceptions for rape, incest and to save the life of the mother.

From Los Angeles Times • Oct. 25, 2024

However, the 2010 constitution, combined with a wider body of law, does allow abortion when "the life or health of the mother is in danger" or when the pregnancy has resulted from rape or incest.

From BBC • Nov. 26, 2023

Both of Missouri’s Republican U.S. senators have said they support abortion in cases of rape and incest.

From Seattle Times • Aug. 30, 2023

"Are you utterly witless? Did you read what he says? The boy Joffrey, he calls him. And he dares to accuse me of incest, adultery, and treason!"

From "A Clash of Kings" by George R.R. Martin