noun
pit toilet; outhouse; non-flushing toilet
A traditional toilet where waste drops directly into a pit or tank below, without flushing. The name is onomatopoeic from the sound of waste dropping. Often contrasted with 水洗便所 (flush toilet).
See also: 汲み取り便所
田舎の祖父母の家にはまだぼっとん便所がある。
My grandparents' house in the countryside still has a pit toilet.
ぼっとん便所は汲み取り式のトイレの一種だ。
A ぼっとん便所 is a type of vault toilet that requires periodic emptying.