The spelling "wast of" is incorrect, and may have been intended as "waste of." In IPA phonetic transcription, this would be pronounced /weɪst ʌv/. The "ai" represents the long "a" sound in "waste," and the "o" in "of" is pronounced as a schwa sound, represented by the symbol "ʌ." It's important to pay attention to correct spelling and pronunciation to avoid confusion or misinterpretation of written or spoken language.
The phrase "wast of" does not have a specific etymology since it is not a widely recognized expression or word in modern English. However, if you are referring to the word "waste", it has a Middle English origin. The word can be traced back to the Old North French word "waster", meaning "to lay waste" or "to destroy". It eventually made its way into Middle English with the same meaning. Over time, the term "waste" evolved to encompass various related meanings such as "to use something in a careless or extravagant manner", as well as referring to barren or uncultivated land.