"Wast one mind" is an archaic way of saying "lost one's mind." The word "wast" is no longer commonly used in modern English, but it was a past tense form of the verb "to be" in Middle English. The pronunciation of "wast" is /wɑst/ with a short "a" sound in the first syllable and a voiceless "t" sound at the end. The word "one" is simply pronounced as /wʌn/ with a short "u" sound. "Mind" is pronounced as /maɪnd/ with a long "i" sound in the first syllable and a voiced "d" sound at the end.