expression, godan verb (-su)
go astray; stray from the right path; become corrupt
Idiomatic expression meaning to deviate from the morally or socially correct path, often implying a fall into wrongdoing or corruption.
彼は若い頃に道を踏み外して、犯罪に手を染めた。
He strayed from the right path in his youth and got involved in crime.
Once you go astray, it's hard to get back on track.