1. mod. not using drugs; not involved with drugs. I’ve been clean for more than a month now.
2. mod. sober; not intoxicated with drugs at the moment. (Almost the same as sense 1) Just being clean for a day is an accomplishment.
3. mod. not breaking any law. (Police and underworld.) I’m clean, officer. You can’t charge me with anything.
4. mod. not carrying a weapon. (Police and underworld.) I frisked him. He’s clean.
5. mod. well-dressed. Now there’s a clean dude!