- Probably an allusion to failing to follow the rules when playing billiards. (Wiktionary)
- From pool2. (American Heritage® Dictionary of the English Language, Fourth Edition)
“A friend of mine on the LAPD Riot Squad said 99 percent of your white-on-Mexican assaults weren’t reported and the Mexicans never took the damn sticks to each other, it was considered dirty pool or whatever.”
These user-created lists contain the word ‘dirty pool’.
Off the straight and narrow; less than straight arrow.
Words from a 2010 'Remember Me' film.
Looking for tweets for dirty pool.