1. slang Currently one who consumes alcohol, especially heavily and frequently. Said especially of alcoholics. My dad was a real mean son of a gun when he was on the sauce. You can tell Tara's been on the sauce again—she's been reeking of booze lately.

2. slang Using performance-enhancing drugs, especially anabolic steroids. The football star has repeatedly denied being on the sauce, though he still refuses to take an official drug test. I knew a guy who went on the sauce in high school trying to get super jacked. I think that junk really messed up his body.