The phrase "wast proud of" may seem like an unusual spelling, but it is actually an archaic form of the phrase "were proud of." In IPA phonetic transcription, the pronunciation of "wast" would be /wɑːst/ which is pronounced like the word "waste" but with a longer "a" sound. This form of the word was commonly used in Middle English and Shakespearean language. Today, we use "were" instead of "wast" in modern English.