Sexual intercourse between persons too closely related to marry (as between a parent and a child).

Roget 961: impurity; uncleanness etc. (filth) 653; immodesty; grossness etc. adj.; indelicacy, indecency; impudicity^†; obscenity, ribaldry, Fescennine, smut, bawdry^†, double entente, equivoque [Fr.].    concupiscence, lust, carnality, flesh, salacity; pruriency, lechery, lasciviency^†, lubricity; Sadism, sapphism^†.    incontinence, intrigue, faux pas [Fr.]; amour, amourette^†; gallantry; debauchery, libertinish^†, libertinage^†, fornication; liaison; wenching, venery, dissipation.    seduction; defloration, defilement, abuse, violation, rape; incest.    prostitution, social evil, harlotry, stupration^†, whoredom, concubinage, cuckoldom^†, adultery, advoutry^†, crim.    con.   ; free love.    seraglio, harem; brothel, bagnio^†, stew, bawdyhouse^†, cat house, lupanar^†, house of ill fame, bordel^†, bordello.    ... show more

Roget 374a: sex, sexuality, gender; male, masculinity, maleness etc. 373; female, femininity etc. 374.    sexual intercourse, copulation, mating, coitus, sex; lovemaking, marital relations, sexual union; sleeping together, carnal knowledge.    sex instinct, sex drive, libido, lust, concupiscence; hots, horns [Coll.]; arousal, heat, rut, estrus, oestrus; tumescence; erection, hard-on, boner.    masturbation, self-gratification, autoeroticism, onanism, self-abuse.    orgasm, climax, ejaculation.    sexiness, attractiveness; sensuality, voluptuousness.    [sexual intercourse outside of marriage] fornication, adultery.    [person who is sexy] sex symbol, sex goddess; stud, hunk.    one-night stand.    pornography, porn, porno; hardcore pornography, softcore pornography; pin-up, cheesecake; beefcake; [magazines with sexual photos], Playboy, Esquire, Hustler.    [unorthodox sexual activity] perversion, deviation, sexual abnormality; fetish, fetishism; homosexuality, lesbianism, bisexuality; sodomy, buggery; pederasty; sadism.    masochism, sado-masochism; incest.    ... show more

Dutch: bloedschande
Polish: kazirodztwo