expression, godan verb (-mu)
commit a crime; pull off a job
Slang used among criminals or in underworld contexts. ヤマ refers to a criminal act or case. Often implies successfully carrying out a planned crime.
See also: 山 (やま)
あの二人は今度大きなヤマを踏んだらしい。
I hear those two pulled off a big job this time.
ヤマを踏む前に、しっかり計画を立てる。
Before committing a crime, they plan carefully.