The word "wast" in the phrase "wast in unison" is an archaic spelling of "was" that was commonly used in Middle English. The IPA phonetic transcription for "wast" is /wɑːst/, with the "a" pronounced as a long "aw" sound. "Unison" is spelled phonetically as /juːnɪsən/, with the stress on the first syllable and the "i" pronounced as a long "ee" sound. Together, these words form a phrase that means "was in agreement or harmony."