also: じゅっちゅうはっく · じゅうちゅうはっく
adverb, noun
in all probability; nine times out of ten
Used to express a very high likelihood; often appears as an adverbial phrase. A yojijukugo (four-character compound).
十中八九、彼は遅刻するだろう。
In all probability, he will be late.
十中八九、明日は雨だ。
Nine times out of ten, it will rain tomorrow.