性せい行こう為い

せ

い

こ

う

い

Freq.FrequencyTop 20,000

Meanings

1

Formal, clinical term for sexual intercourse or sexual activity. Used in medical, legal, or educational contexts.

こと

が

大たい

切せつ

だ

。

It is important to have accurate knowledge about sexual intercourse.

この法ほう律りつでは、同どう意いのない性せい行こう為いは犯はん罪ざいとみなされる。

Under this law, non-consensual sexual acts are considered a crime.

〈人ひと〉と性せい行こう為いをするto have sexual intercourse with someone
未み成せい年ねん者しゃとの性せい行こう為いは法ほう律りつで禁きん止しされている。
Sexual acts with a minor are prohibited by law.
性せい行こう為いに及およぶto go as far as having sex
二人ふたりはその晩ばん、性せい行こう為いに及およんだ。
The two of them ended up having sex that night.
性せい行こう為いを強きょう要ようするto force someone into a sexual act
彼かれは部ぶ下かに性せい行こう為いを強きょう要ようした罪つみで逮たい捕ほされた。

セックスN1
セックス is the everyday, casual loanword for sex, while 性行為 is the formal, clinical term used in medical or legal writing.
性せい交こう
性交 is a formal medical/legal term nearly synonymous with 性行為, but 性行為 is slightly broader and can cover sexual acts beyond intercourse itself.
性せい交こう渉しょう
性交渉 is another formal, somewhat bureaucratic term for sexual relations, used interchangeably with 性行為 in reports and surveys.

性せい教きょう育いく
性行為 means 'sexual act/intercourse' itself, while 性教育 refers to teaching about sexuality, so despite sharing the kanji 性 they are not interchangeable.

性せい行こう為い感かん染せん症しょう
sexually transmitted disease; sexually transmitted infection; STD; STI

Compound of 性 (sei, 'sex, gender') and 行為 (kōi, 'act, deed'). A straightforward Sino-Japanese formation.

He was arrested for coercing a subordinate into a sexual act.