不法滞在（ふほうたいざい、fuhoutaizaい）
- illegal stay

The Japanese word 不法滞在 (ふほうたいざい) directly translates to "illegal stay" or "overstay" in English. It refers to the situation where a foreign national remains in a country after their visa or permission to stay has expired, or where they have entered a country without proper documentation. In essence, it describes a violation of immigration laws.

⚫︎彼はビザが切れた後も不法滞在している。 Translation: He is overstaying after his visa expired. ⚫︎不法滞在の外国人は強制送還される可能性があります。 Translation: Foreigners who are in illegal stay may be deported. ⚫︎不法滞在の罪で逮捕された。 Translation: He/She was arrested for the crime of illegal stay.

This term is used in formal contexts, such as legal proceedings, news reports, and official documents. You would use 不法滞在 when discussing someone's immigration status or when referring to the act of staying in a country illegally. It’s a serious term with legal implications.

不法滞在 is typically written with the kanji 不法 (ふほう) meaning "illegal" or "unlawful," and 滞在 (たいざい) meaning "stay" or "residence." The word is generally written in kanji and hiragana. There are no other common ways to write this word. The okurigana is standard.

There are no perfect synonyms for 不法滞在 that carry the same legal weight, but the following terms are related: ⚫︎ オーバーステイ (ōbā sutei): Overstay, a more informal term. ⚫︎ 不法残留 (ふほうざんりゅう): Illegal residence. This is very close in meaning and often interchangeable with 不法滞在. ⚫︎ 不法入国 (ふほうにゅうこく): Illegal entry (entering a country without permission).

⚫︎ 合法滞在 (ごうほうたいざい): Legal stay. ⚫︎ 適法滞在 (てきほうたいざい): Lawful stay.

彼は不法滞在を理由に日本から強制送還された。 ・Translation: He was deported from Japan due to his illegal stay. ・Explanation: This sentence explains that a person was deported because they were staying in Japan illegally, violating immigration laws.

その会社は不法滞在の外国人労働者を雇っていたことが発覚した。 ・Translation: It was revealed that the company was employing foreign workers who were in illegal stay. ・Explanation: This sentence describes a situation where a company was found to be hiring people who were staying in the country illegally.

The word 不法滞在 is formed by combining the following kanji: ⚫︎ 不 (fu): meaning "not" or "non-". ⚫︎ 法 (hou): meaning "law". ⚫︎ 滞 (tai): meaning "stay" or "delay". ⚫︎ 在 (zai): meaning "to exist" or "to be present". Therefore, the literal breakdown of the word is "not-law stay," or "illegal stay."