noun
public toilet; public restroom; public lavatory
Standard term for a public toilet facility. The cross-reference 公衆トイレ is a more common modern synonym.
See also: 公衆トイレ
公園の公衆便所はいつも清掃が行き届いている。
The public toilet in the park is always well-maintained.
noun
Vulgar slang, derogatory. Used to insult a woman perceived as promiscuous, likening her to a public toilet. Strongly offensive.
あいつは公衆便所みたいな女だ。
That woman is a slut.