The spelling of the word "wast mentioned" may seem a bit confusing at first. The reason for this is because it is written in an old-fashioned form of English, known as Early Modern English. In this form of English, the word "wast" is a contraction of "were" and "thou", meaning "you were". The spelling of "mentioned" remains the same as it is in modern English. In IPA phonetic transcription, "wast" would be transcribed as /wɑːst/ and "mentioned" as /ˈmɛn.ʃənd/.
The phrase "wast mentioned" is not a word with its own etymology. Instead, it is a combination of two separate words: "wast" and "mentioned".
1. "Wast" is the archaic second-person singular past tense of the verb "be" in Middle English. It is derived from the Old English word "wǣre" meaning "were". Over time, "wast" evolved into "wert" and then into the modern English "were".
2. "Mentioned" is derived from the Middle English word "mencionen", which was borrowed from Old French "mentioner" meaning "to mention". This, in turn, came from Latin "mentio" meaning "a calling to mind" or "remembrance".
When combined, the phrase "wast mentioned" essentially means "you were mentioned" or "mentioned in the past".