1. To move on top of something with one or a series of steps. I knew I had put on some weight over the holidays, so I was dreading stepping on the scales again. After the singer was done giving her performance onstage, the principal stepped on to close out the ceremony.
2. To press one's foot down on someone or something. I stepped on the paper to keep it from blowing away in the wind. The police officer stepped on the criminal's hand when she began reaching for her gun.
3. To walk on or over someone or something. Please don't step on the carpet with your muddy shoes! I fell on the ground during the race, and several people just stepped on me before anyone offered to help.
4. slang To dilute or adulterate recreational drugs. It turned out the heroin had been stepped on with fentanyl, which led to nearly 20 fatal overdoses in the area. The gang has been stepping on the cocaine with baking powder and laundry detergent in order to sell more product at a lower cost.
mod. having to do with diluted drugs. (Drugs.) This stuff is too stepped on. It’s sugar, and it won’t do.