1. mod. using drugs; selling drugs; looking for drugs. (Drugs.) Fred spent a year on the street before he was arrested.
2. mod. engaged in prostitution. Mary said, “What am I supposed to do—go on the street?” All three of them went on the street to earn enough money to live.
3. mod. widely known. It’s on the street. There isn’t anyone who hasn’t heard it.
4. mod. on Wall Street or elsewhere in the New York City financial districts. (Similar to sense 3, except that it refers to a specific street. Usually with a capital S.) I heard on the Street today that Apple is buying IBM.
5. mod. at discount prices; as available from discounters. (As if some item were being sold on the street by a peddler.) It lists at $2,200 and can be got for about $1,650 on the street.