An exclamation of surprise. i.e. Yowza! You scared me!
A word signifying approval, often said as an aside to a friend or a slightly audible remark to one's self, i.e. Yowza!, look at her!
A colloquial form of "yes, sir", 1934, popularized by U.S. bandleader and radio personality Ben "The Old Maestro" Bernie (1891-1943).