oz I. abbreviation 1.[Italian onza] ounce 2. ooze II. \ˈäz\noun (-es) Usage: usually capitalized Etymology: from Oz, mythical land in a series of books by L. Frank Baum died 1919 American author : a seemingly ideal or perfect place < the rationalized, suburbanized Oz that is the postwar United States — Verlyn Klinkenborg >