二穴
に
け
つ
Meanings
1
two holes
Literal meaning: two holes or openings. Can refer to any object with two perforations.
This part requires two holes.
2
toilet with separate chambers for urine and feces
Refers to an old-style squat toilet or outhouse with two separate openings. Rare in modern contexts.
In the past, there were toilets with two separate holes.
3
riding double (on a bicycle, motorcycle, etc.)
slangusually written using kana alone
Slang term for two people riding on a single bicycle or motorcycle. Usually written in katakana as ニケツ.
See also: ニケツ
Riding double is dangerous, so let's not do it.